Etymology

From complement +‎ -aryCategory:English terms suffixed with -ary#COMPLEMENTARY. Piecewise doublet of complimentaryCategory:English piecewise doublets#COMPLEMENTARY.

Pronunciation

• (Received Pronunciation) IPA^(key): /ˌkɒmplɪˈmɛnt(ə)ɹi/Category:English 5-syllable words#COMPLEMENTARYCategory:English terms with IPA pronunciation#COMPLEMENTARY

• Audio (Southern England):

  (file)

  Category:English terms with audio pronunciation#COMPLEMENTARY
• (General American) enPR: kŏm'plĭ-mĕnʹtə-rē, -trē, IPA^(key): /ˌkɑmplɪˈmɛnt(ə)ɹi/Category:English 5-syllable words#COMPLEMENTARYCategory:English terms with IPA pronunciation#COMPLEMENTARY
• Homophone: complimentaryCategory:English terms with homophones#COMPLEMENTARY
• Rhymes: -ɛntəɹi, -ɛntɹiCategory:Rhymes:English/ɛntəɹi#COMPLEMENTARYCategory:Rhymes:English/ɛntɹi#COMPLEMENTARYCategory:Rhymes:English/ɛntɹi/4 syllables#COMPLEMENTARY
• Hyphenation: com‧ple‧men‧ta‧ry

Adjective

complementary (comparative more complementary, superlative most complementary)Category:English lemmas#COMPLEMENTARYCategory:English adjectives#COMPLEMENTARYCategory:English entries with incorrect language header#COMPLEMENTARYCategory:Pages with entries#COMPLEMENTARYCategory:Pages with 1 entry#COMPLEMENTARY

1. Acting as a complement; making up a whole with something else.

   I'll provide you with some complementary notes to help you study.Category:English terms with usage examples#COMPLEMENTARY

   The two business partners had complementary abilities: one had excellent people skills, while the other had a head for figures.Category:English terms with usage examples#COMPLEMENTARY

   • 1988, Andrew Radford, Transformational grammar: a first course, Cambridge, UK: Cambridge University Press, page 140:

     Using the terminology we introduced earlier, we might then say that black and white squares are in complementary distribution on a chessboard. By this we mean two things: firstly, black squares and white squares occupy different positions on the board: and secondly, the black and white squares complement each other in the sense that the black squares together with the white squares comprise the total set of 64 squares found on the board (i.e. there is no square on the board which is not either black or white).

     Category:English terms with quotations#COMPLEMENTARY

2. (geneticsCategory:en:Genetics#COMPLEMENTARY) Of the specific pairings of the bases in DNA and RNA.
3. (physicsCategory:en:Physics#COMPLEMENTARY) Pertaining to pairs of properties in quantum mechanics that are inversely related to each other, such as speed and position, or energy and time. (See also Heisenberg uncertainty principle.)

Noun

complementary (plural complementaries)Category:English lemmas#COMPLEMENTARYCategory:English nouns#COMPLEMENTARYCategory:English countable nouns#COMPLEMENTARYCategory:English entries with incorrect language header#COMPLEMENTARYCategory:Pages with entries#COMPLEMENTARYCategory:Pages with 1 entry#COMPLEMENTARY

1. A complementary colour.
2. (obsoleteCategory:English terms with obsolete senses#COMPLEMENTARY) One skilled in compliments.
   • 1600 (first performance), Beniamin Ionson [i.e., Ben Jonson], “Cynthias Reuels, or The Fountayne of Selfe-Loue. […]”, in The Workes of Beniamin Ionson (First Folio), London: […] Will[iam] Stansby, published 1616, →OCLC:

     the hands of the most skilful and cunning complementaries alive

     Category:English terms with quotations#COMPLEMENTARY

3. An angle which adds with another to equal 90 degrees.

Further reading

• James A. H. Murray et al., editors (1884–1928), “Complementary, a. and sb.”, in A New English Dictionary on Historical Principles (Oxford English Dictionary), volume II (C), London: Clarendon Press, →OCLC, page 725.
• “complementary”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.
• William Dwight Whitney, Benjamin E[li] Smith, editors (1911), “complementary”, in The Century Dictionary […], New York, N.Y.: The Century Co., →OCLC.