COMPLIMENT definition: 1. a remark that expresses approval, admiration, or respect: 2. an action that expresses approval…. Learn more. Complement is the term used for a word or words that are needed to complete the meaning of an expression. Most phrases and clauses will include a complement of some kind. If you can't remove it from your sentence, then it's likely to be a complement . This is how complements differ from adjuncts. Adjuncts are optional as they are usually just descriptive. Complements are not optional. They are essential to ensure understanding. Master the word " COMPLIMENT " in English: definitions, translations, synonyms, pronunciations, examples, and grammar insights - all in one complete resource. Complement and compliment sound the same, but they mean very different things. A complement is something that completes or improves something else. A compliment is a polite expression of praise or admiration . For example, “That scarf complements your outfit” vs “She gave me a kind compliment.”