Irreversible binomial

A fixed phrase of two or more joined words

In linguistics and stylistics, an irreversible binomial, frozen binomial, binomial freeze, binomial expression, binomial pair, or nonreversible word pair is a pair of words used together in fixed order as an idiomatic expression or collocation. The words have a semantic relationship usually involving the words and or or. They also belong to the same part of speech: nouns, adjectives, or verbs. The order of word elements cannot be reversed.

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