core
/kɔːr/ (bre, ipa) · [kˈɔr] /kɔːr/ (ame, ipa) · [kˈɔr] /ˈkȯr/ (ame, mw) · /kɔː(r)/ (bre, ipa) · /-kɔːr/ (bre, ipa) · [kˈɔr] /-kɔːr/ (ame, ipa)
core — verb
- corepresent simple I / you / we / they
- cores3rd person singular
- coring-ing form
- coredpast simple
1. to cut away the hard, seed-filled centre of a fruit such as an apple or a pear,
to cut away the hard, seed-filled centre of a fruit such as an apple or a pear, usually before eating it or using it in cooking
Adisa cored the apple and sliced it into thin pieces for the pie.
Before adding the pears to the salad, Salma cored and chopped them.
core and chop + noun for food preparation
The recipe says to core the pears first, then boil them with sugar and cinnamon.
Maja cored six apples in under two minutes using the new kitchen gadget.
Reuben showed his daughter how to core an apple without cutting herself.
文法句型
core + noun (fruit)
用法筆記
Object is always a fruit — usually an apple, pear, or pineapple. The verb is most common in recipe instructions and cooking contexts.
常見錯誤
core — noun
- coresingular
- coresplural
1. The most central, basic, or important part of an idea, system, problem, or set o
The most central, basic, or important part of an idea, system, problem, or set of beliefs — the part that makes everything else possible or meaningful.
The core of the problem is a lack of clean drinking water in the village.
the core of + noun (the most central element)
Putri believes that honesty is at the core of every strong friendship.
at the core of — phrase for stating the essential nature
These three topics form the core of the training course for new nurses.
At its core, the novel is a story about forgiveness and hope.
The company’s core is still manufacturing bicycle parts, not software.
- heart
More emotional or figurative; 'the heart of the matter' suggests feeling, while 'core' suggests logical foundation.
- essence
More philosophical; suggests the fundamental nature that makes something what it is.
- centre
More physical/spatial; 'centre of the city' is concrete, 'core of the argument' is abstract.
文法句型
the core of [something]
at its core
[something] forms the core of [something]
用法筆記
Often used in the fixed phrase 'at its core' to state the essential character of something after removing details.
常見錯誤
2. The tough centre of an apple, pear, or similar fruit where the seeds are held, u
The tough centre of an apple, pear, or similar fruit where the seeds are held, usually removed before eating.
After eating the apple, Jin dropped the core into the compost bin.
drop/throw the core — disposal of fruit remains
Tara cut the pear into four pieces and carefully removed the core.
remove the core — common cooking or eating action
The children learned that the core of a pineapple is too tough to chew.
Adaeze used a small metal tool to scoop out the apple core before baking.
- seed case
A botanical term for the part that holds seeds; less common in everyday language.
文法句型
the core of [a fruit]
[fruit] core
常見錯誤
3. The innermost region of a planet or other space body, where heat and pressure ar
The innermost region of a planet or other space body, where heat and pressure are far greater than at the surface.
Scientists believe that Earth’s core is made mostly of iron and nickel.
Earth’s core — the most common collocation for this sense
The planet’s solid core is surrounded by thick layers of hot liquid rock.
Kevin learned that the Moon’s core is much smaller than Earth’s relative to its size.
Heat rising from the planet’s core drives the movement of continents over millions of years.
- centre
More general term for the middle point; core implies different physical properties from the surrounding layers.
文法句型
[planet]'s core
the core of [planet]
用法筆記
Frequently used in geography and science contexts. Often contrasted with 'crust' (the outer layer) and 'mantle' (the middle layer).
常見錯誤
4. The innermost section of a nuclear power plant where fuel atoms are broken apart
The innermost section of a nuclear power plant where fuel atoms are broken apart to produce heat for making electricity.
Engineers checked the temperature inside the reactor core every hour.
reactor core — common technical noun+noun compound
The nuclear reactor’s core holds fuel rods that contain enriched uranium.
A cooling system surrounds the reactor core to stop it from getting too hot.
Karim watched a documentary about how engineers built the reactor core inside the power plant.
文法句型
reactor core
the core of a nuclear reactor
用法筆記
This is a technical term used in physics and energy-industry writing. In everyday conversation, people usually say 'nuclear reactor' rather than 'reactor core'.
常見錯誤
5. The group of muscles in the middle of your body, including the stomach, lower ba
The group of muscles in the middle of your body, including the stomach, lower back, and hips, that help you stay balanced and move with strength and control.
Sven does twenty minutes of core exercises every morning before breakfast.
core exercises — common fitness collocation
A strong core helps prevent back pain when you lift heavy boxes.
The yoga teacher told the class to engage their core during the balancing pose.
Putri’s running coach said that building core strength would improve her speed.
Iris felt her core working hard as she held the plank position for one minute.
- abdominal muscles
More specific; refers only to the stomach-area muscles, not the full set including back and hips.
- midriff
Refers to the front of the body between chest and waist; less common in fitness contexts.
文法句型
core + noun (exercises, strength, muscles)
[possessive] core
用法筆記
Common in fitness and health contexts. 'Core' here is uncountable when referring to the muscle group as a whole ('build core'), but countable when referring to specific muscle areas ('work your core').
常見錯誤
6. A column-shaped piece of earth, rock, or ice brought up from deep underground by
A column-shaped piece of earth, rock, or ice brought up from deep underground by a special drilling tube, so researchers can study what lies beneath the surface.
The research team pulled a three-meter core of ice from the Antarctic glacier.
core of ice — [material] + core
Each core sample from the ocean floor contains layers of sand, shells, and tiny fossils.
core sample — fixed expression for a sample obtained by drilling
Scientists examine rock cores to learn what the climate was like thousands of years ago.
Cole helped carry the soil cores from the drill site back to the laboratory van.
The ice cores taken from Greenland show pollution levels from the past five centuries.
文法句型
core + of + [material]
core sample
[material] core
用法筆記
Typically used in geology, climate science, and archaeology. Core samples are stored in long trays and studied layer by layer.
常見錯誤
7. The innermost section of a manufactured or natural object, running along its len
The innermost section of a manufactured or natural object, running along its length and often made of a different material from the outer layers.
The core of the climbing rope is made of strong nylon fibers twisted tightly together.
The thin graphite core inside a pencil is surrounded by a wooden casing.
[material] core — core made of a specific substance
Workers drilled into the core of the concrete pillar to check its strength.
The core of the foam mattress is made of dense memory foam for better support.
At the core of the old tree, the wood had become soft and hollow inside.
- outer layer
the parts that surround and enclose the core
- surface
the outermost boundary of an object
用法筆記
Applies to manufactured objects and natural formations where an inner layer differs from the outer layer. Not used for fruit (sense 2) or planets (sense 3).
常見錯誤
8. A small, tightly connected set of people who are the main participants in an act
A small, tightly connected set of people who are the main participants in an activity, organization, or movement, and on whom its continued operation depends.
A core of twenty volunteers keeps the neighborhood library open on weekends.
core of + number + role
The dance company's core consists of twelve dancers who train together daily.
possessive: [group]'s core
Brooke is part of the core team that organizes the annual science fair.
Only the core members of the club knew about the surprise party.
Léa joined the core of experienced engineers who designed the new bridge.
- nucleus
more formal — often used for the central part of an organization around which others gather
- backbone
emphasises the essential supporting role of the group
- inner circle
emphasises exclusivity and closeness to leadership
用法筆記
Typically refers to a stable, long-term group rather than a temporary team. The core may be surrounded by a larger, looser set of occasional participants or peripheral members.
常見錯誤
core — adjective
- corepositive
- corercomparative
- corestsuperlative
1. describing the part or aspect of something that is the most important and fundam
describing the part or aspect of something that is the most important and fundamental, serving as the foundation that everything else depends on.
The core message of her speech was that small daily habits lead to big changes.
attributive: before a noun (core message)
Good customer service is a core part of the hotel's business strategy.
Addressing the core problem of water shortages requires effort at every level.
The designers returned to the core question of what users actually need from the app.
- fundamental
More formal; emphasises the foundational nature rather than importance ranking
- essential
Closer in meaning, but 'essential' focuses on necessity rather than centrality
- primary
Focuses on rank or order (first in importance) rather than being the central foundation
- peripheral
Describes something on the edges, not central
文法句型
core + noun
2. relating to the values, beliefs, or principles that are most important to a pers
relating to the values, beliefs, or principles that are most important to a person, group, or system and that define their identity or purpose.
Honesty is a core belief that the school tries to teach its students from day one.
collocation: core belief
Respect for different opinions is core to the way Lin's team makes decisions.
predictive use: is core to [something]
The organisation's core values include fairness, transparency, and community service.
Protecting children's safety is a core principle that guides every policy decision.
- fundamental
Stronger emphasis on being the necessary base or foundation
- central
Focuses on the idea being at the centre of a set of related ideas
文法句型
core + (value, belief, principle, idea)
用法筆記
Often used with nouns like 'value', 'belief', 'principle' to describe what defines a person or group. Can also appear predicatively: 'is core to [something]'.
常見錯誤
3. describing the main, most essential, or most profitable activities, products, or
describing the main, most essential, or most profitable activities, products, or services that a company or organisation focuses on.
The company decided to sell its smaller brands and focus on its core business.
collocation: core business
Software development is the firm's core activity and generates most of its income.
The publishing house cut costs by outsourcing everything except its core operations.
Our core customers are families looking for reliable and affordable home appliances.
- peripheral
Describes activities that are on the edges, not central to the business
- secondary
Describes activities that are less important or supporting
文法句型
core + (business, activity, operation, product, customer)
用法筆記
Typically used before nouns that name a type of business activity (business, operation, product, service, activity). Not used for one-time projects or side ventures.
4. describing the set of courses or subjects that all students in a programme must
describing the set of courses or subjects that all students in a programme must study as a compulsory part of their education.
All first-year engineering students must take the same core courses in mathematics and physics.
collocation: core courses
The university redesigned its core curriculum to include more practical writing assignments.
Advanced chemistry is optional, but the core science classes are compulsory for everyone.
The school's core subjects include English, mathematics, science, and social studies.
- required
More general; used across contexts beyond education
- compulsory
Stronger emphasis on obligation; common in British English
- mandatory
More formal; often used in official documents
文法句型
core + (subject, course, curriculum)
用法筆記
Commonly used with 'subject', 'course', 'curriculum'. Not used for optional or elective courses.
常見錯誤
5. relating to the group of muscles in the torso — including the abdomen, lower bac
relating to the group of muscles in the torso — including the abdomen, lower back, hips, and pelvis — that stabilise the body during movement and help maintain balance.
The yoga instructor told the class to keep their core muscles tight during the pose.
collocation: core muscles
Strong core strength helps prevent back injuries when lifting heavy objects at work.
The physical therapist designed exercises to strengthen Wei's core after the surgery.
Runners benefit from core training because it improves balance and running efficiency.
文法句型
core + (muscles, strength, training, exercise)
用法筆記
Often used in fitness, sports medicine, and rehabilitation contexts. Typically attributive before 'muscles', 'strength', 'training', 'exercise'. Can also be used as a noun in fitness contexts ('work on your core').
常見錯誤
core — abbreviation
1. a US civil rights organization, founded in 1942, that fought against racial segr
a US civil rights organization, founded in 1942, that fought against racial segregation through nonviolent protest, most famously the Freedom Rides of 1961
In 1961, CORE organized the Freedom Rides to challenge segregation on interstate buses across the South.
CORE organized [event] — subject-verb pattern for describing the group's actions
The nonviolent methods used by CORE inspired many other groups working for social change.
Lotte's grandfather joined CORE in 1962 and took part in the march from Selma to Montgomery.
CORE trained volunteers in peaceful protest techniques before sending them to sites across the South.
The history textbook describes how CORE helped end segregation in public transportation.
用法筆記
Often used in past-tense discussions of US civil rights history. The name is pronounced as one word /kɔːr/, not as separate letters.
core — suffix
1. added to the end of a word to name a fashion or lifestyle trend that follows a c
added to the end of a word to name a fashion or lifestyle trend that follows a certain look or feeling, especially one shared online
Her outfit was pure normcore — plain jeans, a white T-shirt, and simple sneakers.
'normcore' — core added to 'normal' for an ordinary, everyday style
Cottagecore has become popular online, with people sharing pictures of baking bread and gardening.
Otis created a gorpcore jacket by sewing together parts of old camping tents and sleeping bags.
The barbiecore trend filled bedrooms and clothes with bright pink colours in 2023.
Adina follows several '-core' accounts on social media to find new decorating ideas for her room.
文法句型
[base word] + core
用法筆記
New '-core' words appear frequently as online trends change. The base word is usually a noun (cottage, barbie, gorp) or an adjective (normal) describing the style.
常見錯誤
❖ 'I like this core style.' ✅ 'I like this normcore style.' — '-core' is a suffix that must attach to a base word; it cannot stand alone as an adjective.