compound

/ˈkɒmpaʊnd/ (bre, ipa) · /ˈkɑːmpaʊnd/ (ame, ipa) · /ˈkäm-ˌpau̇nd/ (ame, mw) · /kəmˈpaʊnd/ (bre, ipa) · /kəmˈpaʊnd/ (ame, ipa) · /ˈkɒm.paʊnd/ (bre, ipa) · /ˈkɑːm.paʊnd/ (ame, ipa)

compound — noun

  • compoundsingular
  • compoundsplural

1. a material created when atoms from several different chemical elements bond toge

1.名詞B2
釋義

a material created when atoms from several different chemical elements bond together in a fixed ratio by weight

例句

Caio's science class studied how sodium and chlorine join to form the compound known as table salt.

collocation: form a compound

Water is a simple compound made of two hydrogen atoms linked to one oxygen atom.

同義詞
  • substance

    broader; any kind of material, not necessarily chemically bonded

  • material

    even broader; refers to what something is made of

  • chemical

    can refer to any chemical substance, including pure elements

反義詞
  • element

    a pure substance made of only one type of atom, not chemically combined

用法筆記

Common in chemistry contexts. Often used with the verb 'form': 'Sodium and chlorine form a compound.'

常見錯誤

Water is a mix of hydrogen and oxygen.
Water is a compound of hydrogen and oxygen.
💡a 'mix' can have any proportion; a 'compound' has a fixed chemical formula.

2. something created by combining several separate elements, such as ingredients, q

2.名詞B2
釋義

something created by combining several separate elements, such as ingredients, qualities, or components

例句

The sauce is a delicious compound of tomatoes, fresh herbs, and olive oil.

compound of [ingredient 1] + [ingredient 2] + [ingredient 3]

Hoa's breathing problems were caused by a compound of dust, smoke, and pollen in the air.

同義詞
  • combination

    more general; does not imply the parts blend into a single thing

  • mixture

    parts are physically combined but not chemically bonded

  • blend

    suggests the parts are smoothly mixed, often of liquids or flavours

  • composite

    emphasises that the parts remain separately identifiable

常見錯誤

The air is a compound of gases.' (in everyday speech)
The air is a mixture of gases.
💡'compound' in everyday use is less common than 'mixture' for non-chemical combinations.

3. a term formed by joining several existing words together, which can be written a

3.名詞B2
釋義

a term formed by joining several existing words together, which can be written as a single unit, separate items, or linked by hyphens

例句

Kian learned that 'mother-in-law' is a hyphenated compound in English grammar.

hyphenated compound

The word 'bus stop' is a compound noun written as two separate words.

同義詞
  • portmanteau

    blends parts of two words, like 'brunch' from 'breakfast' + 'lunch'; narrower than compound

  • derivative

    formed by adding prefixes or suffixes, not by joining whole words

用法筆記

The spelling of compound words varies: closed (bedroom), open (bus stop), or hyphenated (mother-in-law). Learner dictionaries mark this in each entry.

常見錯誤

Firefly is a compound word.' (stating only the fact)
The compound firefly is a word formed from fire and fly, but it refers to an insect, not a burning fly.
💡learners benefit from knowing how the parts relate to the meaning.

4. a walled or fenced piece of land containing several buildings, often forming a s

4.名詞B2
釋義

a walled or fenced piece of land containing several buildings, often forming a single secure site

例句

The embassy compound was surrounded by tall concrete walls and security cameras.

embassy compound with security walls

The Watanabe family lived inside a large compound with several smaller houses and a garden.

同義詞
  • enclosure

    more general; can be a small fenced area without buildings

  • complex

    a group of buildings, but not necessarily walled or enclosed

  • campus

    a university or company site, typically open rather than walled

用法筆記

Often used for embassies, military bases, prisons, temples, schools, or family estates. Suggests some level of security or separation from the outside.

常見錯誤

Our school is in a compound.' (for a single building on an open campus)
Our school is in a compound surrounded by a wall.
💡add a detail that shows the boundary.

compound — verb

compound — adjective