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Collocation

(Definitions)

Collocation is the relationship between two words or groups of words that often go together and form a common expression. If the expression is heard often, the words become 'glued' together in our minds. 'Crystal clear', 'middle management' 'nuclear family' and 'cosmetic surgery' are examples of collocated pairs of words. Some words are often found together because they make up a compound noun, for example 'riding boots' or 'motor cyclist'.