retroactive

Etymology

It is borrowed from French rétroactif (“casting or relating back”),^{[2][3][4][5][6]} recorded in Middle French from 1510,^[7] from Latin retroāctus, the past participle of retroagō (“to drive back, turn back”),^[4][3][2][5] formed from retrō (“back”) and agō (“to drive, set in motion”),^[4][2][5] from Proto-Indo-European *ag- (“to drive, draw out or forth, move”).^[2][4] The revised OED instead takes it as formed within English from retro- and active, after the French word, and the Shorter Oxford and Dictionary.com analyse it in the same way.^[7][8][9] The OED also compares Medieval Latin retroactivus (“far back into the past”) (1425), Spanish retroactivo, Portuguese retroactivo and Italian retroattivo (1798).^[7]

Earliest recorded meaning

Both "moving or driving back" and "extending to past matters", of a law or regulation: 1611, in Cotgrave's French–English dictionary.^[7][3][5]

Semantic evolution

The legal sense, of powers and enactments that apply to circumstances which occurred before they were made, became the main one;^[2][7] Black's Law Dictionary gives retrospective as another term for it.^[10] The rare physical sense, "operating in a backward direction", has stayed rare.^[8][7] From 1822 the word was also used of anything directed backwards in time,^[7] and a sense "reactive, reciprocal" is recorded only from 1799 to 1802.^[7] In psychology, from 1888, it describes effects on the memory of earlier learning, as in retroactive inhibition,^[7] a sense French had used in 1887.^[7] Merriam-Webster Unabridged also records it of a pay rise that takes effect from an earlier date.^[5]

Timeline

• 1611 – driving back; of a law, extending to past matters.^[7][3]
• 1799 – reactive, reciprocal (rare; obsolete after 1802).^[7]
• 1822 – directed backwards in time.^[7]
• 1888 – in psychology, affecting the memory of what was learned before.^[7]

Meanings

Adjective

1. Taking effect from a date in the past, or extending to matters that happened before it was made, as a law, tax or ruling: The council approved a retroactive cut in parking fees.^{[5][11][4][10][7]}
2. Of an increase in pay, effective from an earlier date.^[5][4]
3. (psychology) Affecting the memory of what was learned or experienced earlier.^[7][8]
4. (rare) Acting in a backward direction; driving back.^[7][8]

Word family

• retroactively
• retroactivity
• nonretroactive

Related words

• retroaction
• retroact
• active
• act
• agent

Usage notes

Black's Law Dictionary treats retroactive and retrospective as the same term in law.^[10] The first edition of the OED (1908) also gave a pronunciation with /riːtrəʊ-/ for the first element.^[7]

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
3. ^ a b c d Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
4. ^ a b c d e f The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
5. ^ a b c d e f g Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
7. ^ a b c d e f g h i j k l m n o p q r Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
8. ^ a b c d Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
9. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
10. ^ a b c Garner, Bryan A., ed. (2004), Black's Law Dictionary, 8th ed., St. Paul, Minn.: Thomson West
11. ^ Collins English Dictionary (2023), Glasgow: HarperCollins