Etymologically
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react

This is the current revision of this entry, as edited by bogdan on 16 October 2026 at 13:18. This address is a permanent link to this version.
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Pronunciation

  • IPA: /ɹiːˈækt/[1]

Etymology

It is formed from re- and act,[2][3][4] originally suggested by Medieval Latin react-, the past participle stem of reagere, to do again.[5][4][6]

Earliest recorded meaning

To exert an opposite action on the agent acting upon it: 1644 in the OED and MWU, the 1640s in Etymonline.[7][6][2]

Semantic evolution

To act in response to a stimulus is from 1656.[7][3] In chemistry, of reagents, it is from 1797,[7] and to act in opposition to a force from 1861.[7] To move or tend in a reverse direction is from 1875.[7][3] The separate re-act, to perform again, with the full prefix, is from the 1650s.[2] Reaction is 17th-century, and reactionary 19th-century.[3]

Timeline

  • 1644 – to act in return.[7]
  • 1656 – to respond to a stimulus.[7]
  • 1797 – in chemistry.[7]
  • 1861 – to act against a force.[7]
  • 1875 – to tend backwards.[7]

Modern meaning

Verb

  1. To act or behave in response to something.
  2. To respond badly to a substance such as a drug.
  3. (chemistry) To undergo a chemical reaction.
  4. (react against) To act in opposition to something.

Word family

  • overreact
  • reactance
  • reactant
  • underreact
  • reactive
  • reactor

References

  1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  3. ^ a b c d Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
  4. ^ a b Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
  5. ^ Pearsall, Judy, ed. (1998), The New Oxford Dictionary of English, Oxford: Clarendon Press
  6. ^ a b Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
  7. ^ a b c d e f g h i j Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press