prime
/praɪm/ (bre, ipa) · /praɪm/ (ame, ipa) · /ˈprīm/ (ame, mw)
prime — adjective
- primepositive
- primercomparative
- primestsuperlative
1. ranking above all others in importance, value, or influence — for example, the p
ranking above all others in importance, value, or influence — for example, the prime reason for a decision or a person's prime concern in a difficult situation.
The prime reason for the project delay was a lack of funding.
prime + reason (attributive use showing main cause)
Ezra's prime concern during the storm was his family's safety.
prime + concern for something that matters most
Reducing child poverty remains a prime objective for the government.
Stefan's prime motivation for learning Mandarin was to communicate with his wife's family.
文法句型
prime + noun
用法筆記
This sense is almost always used before a noun (attributive). You would not say 'This reason is prime' — instead say 'This is the prime reason.'
常見錯誤
2. having the highest standard of excellence or the best grade available on the mar
having the highest standard of excellence or the best grade available on the market — used especially for food, materials, and land.
The restaurant serves only prime cuts of beef from local farms.
prime + cut (quality grade of meat)
Camila bought a prime piece of land near the river for her vineyard.
prime + piece of land (best location)
Tara picked the prime spot on the beach, right by the water.
The hotel occupies a prime location in the city centre, near all the main museums.
- excellent
broader meaning, not limited to commercial grading
- top-quality
more informal; used in advertising and casual speech
- premium
suggests higher price as well as higher quality
- inferior
lower in quality or grade
- substandard
below the expected level of quality
文法句型
prime + noun
用法筆記
Common in shopping, real estate, and food-industry contexts. 'Prime real estate' refers to land in the best location, and 'prime beef' refers to meat graded as top quality.
常見錯誤
3. (of a whole number larger than 1) having no whole-number divisors other than 1 a
(of a whole number larger than 1) having no whole-number divisors other than 1 and itself — for instance, 7 can only be split into 1 × 7.
The number 7 is prime because no smaller number divides it evenly except 1.
is prime — predicate use after linking verb
Rin learned to list all prime numbers between 1 and 50 in maths class.
prime number — attributive before noun
Sahil's maths teacher asked the class to circle all the prime numbers on the worksheet.
Zola showed her younger brother that 7 is a prime, because nothing except 1 and 7 divides it.
- composite
having factors other than 1 and itself
文法句型
prime number/number is prime
用法筆記
Unlike the other adjective senses, this one can be used both before a noun (a prime number) and after a linking verb (the number 7 is prime).
常見錯誤
prime — noun
- primesingular
- primesplural
1. the period in a person's life when they are at their peak in terms of physical s
the period in a person's life when they are at their peak in terms of physical strength, energy, health, or professional success.
Professional athletes often reach their physical prime in their mid-twenties.
reach one's prime — verb + noun collocation
Rachid was an outstanding violinist in his prime, touring concert halls across Europe.
in one's prime — fixed prepositional phrase
The photographer captured Maja in the prime of her career as a fashion model.
Bilal retired from competitive swimming while still in his physical prime.
- peak
more general; can also apply to non-human things like performance or demand
- heyday
more literary; suggests a past golden period
- golden age
broader; can refer to a civilisation or field, not just an individual
- decline
the period after one's prime when abilities fade
文法句型
in one's prime
past one's prime
用法筆記
Used mainly in the fixed phrases 'in one's prime', 'past one's prime', and 'the prime of [someone's] life/career'. Rarely used alone without a possessive or a modifying phrase.
常見錯誤
2. the written symbol (′) that follows a number or letter, indicating feet in lengt
the written symbol (′) that follows a number or letter, indicating feet in lengths, minutes in angles or timekeeping, or marking a related character as different from the original.
The room measured 12′ by 15′, which means twelve feet by fifteen feet.
′ symbol = feet — measurement notation
In the formula, a′ represents the new value after the calculation.
′ symbol = derivative or second version
The architect wrote 'ceiling height 10′' on the plan, meaning ten feet.
In calculus class, f′(x) is read as 'f prime of x' and stands for the derivative.
文法句型
[number]'
[letter]'
用法筆記
Distinguish from the double prime (″) used for inches or seconds. In casual writing, a straight apostrophe (') is often used instead of the proper prime symbol (′).
3. a whole number greater than 1 that can be divided exactly only by 1 and itself.
a whole number greater than 1 that can be divided exactly only by 1 and itself.
The numbers 2, 3, 5, 7, and 11 are all primes because each one has exactly two factors.
primes — noun plural for prime numbers
Tomás had to list every prime under 100 for his homework assignment.
Mathematicians have been trying to find patterns in the distribution of primes for centuries.
Bilal had trouble remembering which numbers under 30 were primes during the test.
- prime number
the full form; more explicit in educational contexts
- composite number
a number with factors other than 1 and itself
文法句型
a prime
the primes
用法筆記
Often used interchangeably with 'prime number' in mathematical contexts. The shortest prime is 2, which is also the only even prime.
常見錯誤
prime — verb
- primepresent simple I / you / we / they
- primes3rd person singular
- priming-ing form
- primedpast simple
1. to give someone information, instructions, or warnings ahead of time so that the
to give someone information, instructions, or warnings ahead of time so that they are ready to handle a particular situation well.
The press secretary primed the journalists with prepared answers before the briefing.
prime + person + with + information
Niran primed his younger sister on what to say during the college interview.
prime + person + on + topic
The team was well primed for the debate after weeks of research.
The agent primed the actress for the interview with a list of likely questions.
文法句型
prime + person + for + situation
prime + person + with + information
用法筆記
Often used in the passive ('be primed') or followed by 'with' (information) or 'for' (a situation). The focus is on mental or verbal preparation, not physical training.
常見錯誤
2. to cover a surface such as wood, metal, or plaster with a first layer of special
to cover a surface such as wood, metal, or plaster with a first layer of special paint or coating that prepares it for the final colour.
Before painting the wall, Lucas primed it with a white undercoat.
prime + surface + with + undercoat
The carpenter primed the wooden door to seal it against moisture.
You should always prime bare metal before applying the top coat.
After sanding the table, Stefan primed the surface before painting it dark blue.
文法句型
prime + surface
prime + with + primer
用法筆記
Common in DIY and professional painting instructions. The special paint used in this step is called 'primer' (noun). Most surfaces need priming before the final paint will stick properly.
常見錯誤
3. to load the firing mechanism of a bomb, mine, or gun so that it can be discharge
to load the firing mechanism of a bomb, mine, or gun so that it can be discharged or set off at the right moment.
The soldiers primed the explosives and moved to a safe distance.
prime + explosives — standard military collocation
Eitan carefully primed the old rifle before taking aim at the target.
The device was primed to detonate as soon as the door opened.
The technician primed the detonator and connected it to the timing mechanism.
- disarm
to remove the firing mechanism or make safe
文法句型
prime + bomb/gun
be primed to explode/fire
用法筆記
In modern civilian language, this sense is most common in news reports about military operations or in crime fiction. The related noun is 'primer', meaning the small charge used to set off a larger explosive.