(also collocate ) a word or phrase that is often used with another word or phrase, in a way that sounds correct to people who have spoken the language all their lives, but might not be expected from the meaning:
In the phrase "a hard frost", "hard" is a collocation of "frost" and "strong" would not sound natural.
B2 [C] the combination of words formed when two or more words are often used together in a way that sounds correct:
The phrase "a hard frost" is a collocation.
› [U] the regular use of some words and phrases with others, especially in a way that is difficult to guess