instantaneous

Etymology

It is borrowed from Medieval Latin īnstantāneus with the English suffix -ous,^[2] the Medieval Latin word being made from the stem of Latin īnstāns (“present”),^[3][4][5] on the pattern of mōmentāneus,^[2][4][5] with an ending like that of subterrāneus.^[6] Etymonline instead forms it from the English noun instant on the model of spontaneous.^[7] Compare French instantané, recorded from 1734.^[2] The Latin participle is from īnstō (“to stand near, be at hand; to urge”),^[2][7] formed from in- (“in”) and stō (“to stand”),^[2][7] from Proto-Indo-European *sta- (“to stand, make or be firm”).^[7]

Earliest recorded meaning

Occurring or done in an instant, without any perceptible lapse of time: 1651, in Richard Baxter's Plain Scripture Proof of Infants Church-membership.^[2][6][8] Etymonline dates the adjective to the 1650s, but the adverb instantaneously to the 1640s.^[7]

Semantic evolution

Johnson (1755) defined the word as done in an instant, acting at once with no perceptible succession.^[9] The later uses in the OED are mostly technical: in dynamics, from 1837 in Babbage, it describes what exists at one particular instant, as in instantaneous axis and instantaneous centre of rotation.^[2] In photography, from 1851, it was applied to an exposure of short duration set by a shutter.^[2] The 20th century added the instantaneous water heater (1935) and a gramophone record whose grooves are cut directly during recording (1937).^[2] Mathematics uses it for the limit of an average value as the time interval shrinks.^[10]

Timeline

• 1651 – occurring in an instant, without perceptible lapse of time.^[2][8][6]
• 1837 – existing at one particular instant, in dynamics.^[2]
• 1851 – of a photographic exposure, brief and set by a shutter.^[2]
• 1888 – instantaneous grip vice, a mechanical tool.^[2]
• 1935 – instantaneous water heater, a geyser.^[2]
• 1937 – of a gramophone record, cut directly during recording.^[2]

Meanings

Adjective

1. Happening or finished with no perceptible delay; immediate: The effect of the anaesthetic was instantaneous.^[3][10][6]
2. Done or made as fast as possible, with no delay on purpose: She sent an instantaneous answer to the invitation.^[3][6]
3. Present or occurring at one particular instant, as instantaneous velocity.^[3][6][2]
4. (mathematics) Equal to the limit of the average value of a variable as the time interval approaches zero.^[10]
5. Of a sound recording, usable as soon as it is recorded.^[6][2]

Word family

• instantaneity
• instantaneously
• instantaneousness
• coinstantaneous

Related words

• instant
• momentaneous
• simultaneous
• spontaneous
• stand

References

1. ^ 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 Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
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. ^ a b Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
6. ^ a b c d e f g Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
7. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
8. ^ a b Merriam-Webster's Collegiate Dictionary (2003), 11th ed., Springfield, Mass.: Merriam-Webster
9. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
10. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins