English Reference
verb · noun

complement

v. · n.
US /ˈkɑmpɫəmənt/ UK /kˈɒmplɪmənt/ com·ple·ment UK spelling complementing, complements

  1. 01 B2 Upper Intermediate

    v.to add to something in a way that improves it or makes it perfect.

    v.to contribute extra features to someone or something in such a way as to improve or emphasise their qualities.

    Simple

    The blue tie really complements your grey suit.

    In context

    The minimalist production design complements the stark, emotional themes of the play without distracting the audience from the performances.

    Pitfall
    The wine complimented the meal perfectly. The wine complemented the meal perfectly.

    Do not confuse 'complement' (to complete) with 'compliment' (to praise).

  2. 02 B2 Upper Intermediate

    n.a person or thing that goes well with something else.

    n.a thing that contributes extra features to something else in a way that improves or emphasises its quality.

    Simple

    The delicious sauce was the perfect complement to the grilled fish.

    In context

    The new CEO's focus on operational efficiency proved to be a vital complement to the founder's creative vision.

  3. 03 C1 Advanced Formal

    n.the total number or amount of people or things needed for something.

    n.the full number or quantity required or allowed to make something complete.

    Simple

    The ship finally had its full complement of sailors and was ready to sail.

    In context

    The department is currently operating with a full complement of staff for the first time since the restructuring began last year.

    totalquotafull house
  4. 04 C1 Advanced Technical Linguistics

    n.a word or phrase that follows a verb and gives more information about the subject or object.

    n.a word or phrase, especially an adjective or noun, that is used after a linking verb to complete the predicate.

    Simple

    In the sentence 'She seems happy', the word 'happy' is a complement.

    In context

    The professor explained that while some verbs are intransitive, others require a complement to form a grammatically complete sentence.

    Usage

    In the sentence 'He is a doctor', the phrase 'a doctor' is a subject complement.

  5. 05 C1 Advanced Technical Math

    n.an amount or set that, when added to another, makes a whole.

    n.the amount or set required to complete a whole, such as an angle that makes a right angle or a set of elements not in a given subset.

    Simple

    The complement of a 30-degree angle is a 60-degree angle.

    In context

    In set theory, the absolute complement of set A consists of all elements in the universal set that are not members of A.

Don't confuse

complement vs compliment — Compliment is a polite expression of praise, while complement is something that completes or improves another thing.

Veteran Andreas Christensen complements Cubarsi in central defence.

Al Jazeera· 14 Aug 2026

The Government has asked the UN to complement the national response, with initial priorities including temporary shelter, health, food security and protection .

UN News· 11 Aug 2026

Etymology 1

From Middle English complement, from Latin complēmentum (“that which fills up or completes”), from compleō (“to fill up; to complete”) (English complete). Doublet of compliment. The verb is from the noun.

Etymology 2

See compliment.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Latin complēmentum
Level C1 · Advanced
Frequency Frequent
Updated