A grouping of words in a sentence WordNet 3.0 & Open English WordNet

In corpus linguistics, a collocation is a series of words or terms that co-occur more often than would be expected by chance. Wikipedia

Frequent occurrence of words next to each other Wikidata

A sequence of two or more words that often appear together. OmegaWiki

A sequence of words or terms that co-occur more often than would be expected by chance (i.e., the statistically significant placement of particular words in a language), often representing an established name for, or idiomatic way of conveying, a particular semantic concept. Wiktionary