Etymologically
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complementary

This is the current revision of this entry, as edited by bogdan on 31 October 2026 at 06:26. This address is a permanent link to this version.
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Pronunciation

  • /ˌkɑmplɪˈmɛnt(ə)ɹi/[1]
  • UK: /ˌkɒmplɪˈmɛnt(ə)ɹi/[1]

Etymology

It is formed from English complement + -ary,[2][3][4] and the Shorter Oxford takes it from complemental with the same suffix.[5] The OED compares French complémentaire, from which Merriam-Webster Unabridged derives the modern word.[2][6] complement is from Latin complēmentum (“that which fills up or completes”), from compleō (“to fill up”), the source of complete.[2][3][7]

Earliest recorded meaning

As a noun, "a master of accomplishments": 1616, in Jonson's Cynthia's Revels.[2] As an adjective, ceremonious or full of compliments: 1628, in J. Earle's Micro-cosmography,[2] the 1620s in Etymonline.[3]

Semantic evolution

The early senses belong to complement in its old meaning of courtesy and ceremony, which from about 1655 to 1725 was taken over by the French-derived compliment;[2] the sense "ceremonious" died out after 1657, and Etymonline notes that it now goes with the other spelling.[2][3] The modern sense, forming a complement or completing each other, Etymonline finds by 1794, of the French Revolutionary calendar,[3] and the OED from 1835, with "mutually completing" from 1860.[2] In science it took fixed uses: complementary colours, which together give white light (by 1814 in Etymonline, 1829 in the OED), and complementary angles, which make a right angle (1829);[3][2] in mathematics (1841), and in linguistics, complementary distribution (1934).[2] Complementary medicine, treatments offered beside orthodox medicine, is recorded from 1981.[2]

Timeline

  • 1616 – noun, a master of accomplishments (obsolete).[2]
  • 1628 – ceremonious (obsolete by 1657).[2]
  • 1794 – forming a complement, of the French Revolutionary calendar.[3]
  • 1829 – complementary angles and complementary colours.[2]
  • 1835 – forming a complement, completing.[2]
  • 1860 – of two things, completing each other.[2]
  • c. 1865 – noun, a complementary colour.[2]
  • 1934 – linguistics, complementary distribution.[2]
  • 1981 – complementary medicine.[2]

Meanings

Adjective

  1. Completing something, or of two or more things, making up for each other's lacks so as to form a balanced whole: The two partners have complementary skills.[8][6][2]
  2. Of two angles, adding up to 90 degrees.[5][2]
  3. Of colours, producing white or grey when combined.[2][6]
  4. Relating to complementary medicine, treatment used alongside orthodox medicine.[8][2]
  5. (mathematics, logic) Of two sets, mutually exclusive and together covering every case.[8]
  6. (obsolete, 1628–1657) Ceremonious.[2][5]

Noun

  1. Something in a complementary relation to another, especially a complementary colour.[6][2]

Word family

  • complementarily
  • complementariness
  • complementarity
  • complementary distribution
  • complementary angles
  • complementary medicine

References

  1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g h i j k l m n o p q r s t u v w x y Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
  3. ^ a b c d e f g Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  4. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
  5. ^ a b c Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
  6. ^ a b c d Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
  7. ^ The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
  8. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins