From Longman Dictionary of Contemporary Englishrelative clauseˌrelative ˈclause ●●○ noun [countable] technicalSLG a part of a sentence that has a verb in it, and is joined to the rest of the sentence by ‘who’, ‘which’, ‘where’ etc, for example the phrase ‘who lives next door’ in the sentence ‘The man who lives next door is a doctor.’
Examples from the Corpus
relative clause• A relative clause counts as dependent whereas an adjective modifying a noun clearly does not.• The most notable is the relative pronoun that, which can only be used with a restrictive relative clause. 