inconceivable

Etymology

It is formed from English in- + conceivable, with the negative prefix meaning "not".^{[2][3][4][5][6]} Conceivable itself is formed from conceive and -able, and is recorded from the mid-15th century.^[3] The OED compares French inconcevable, recorded in 1617,^[2] and Johnson derived the English word from the French one.^[7] Etymonline notes that Old English had unasmeagendlic for the same idea.^[3]

Earliest recorded meaning

That cannot be conceived or imagined: Merriam-Webster dates the first known use to 1624,^[6] and Dictionary.com to 1625–35.^[5] Etymonline dates it to the 1630s.^[3] The 1989 edition of the OED had a first record from before 1631,^[8] while the current OED begins its quotations in 1646, with H. Lawrence's Of Communion and Warre with Angels.^[2]

Semantic evolution

From the start the word was often used with exaggerating force, for something hardly credible or beyond reckoning rather than strictly unthinkable.^[2] In 1655 H. More used it as a term of philosophy, and the OED records several technical distinctions of meaning in that use.^[2][8] Johnson (1755) defined it as "incomprehensible; not to be conceived by the mind", quoting Hammond on Christ's "divine inconceivable promises".^[7] From 1706, in I. Watts, it was also a noun, a thing or quality that cannot be conceived.^[2] The Shorter Oxford also records a colloquial use for "very remarkable, extraordinary".^[4]

Timeline

• 1624 – impossible to conceive or imagine; unthinkable.^[6] The current OED's first quotation is from 1646, the 1989 edition's from before 1631.^[2][8]
• 1655 – as a philosophical term.^[2]
• 1706 – noun, something that cannot be conceived.^[2]

Meanings

Adjective

1. Impossible to imagine or form an idea of, especially without direct experience: For someone born deaf, the sound of a violin is inconceivable.^[6][9][2]
2. Too unlikely or shocking to be accepted or allowed; unthinkable: Defeat by such a weak team seemed inconceivable.^[6][9]
3. (colloquial) Hardly credible; very remarkable or extraordinary.^[4][2]
4. (philosophy) Not capable of being conceived by the mind.^[2]

Noun

1. Something that cannot be conceived.^[2][4]

Word family

• inconceivability
• inconceivably
• inconceivableness

Related words

• conceive
• conceivable
• conception

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ 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
5. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
6. ^ a b c d e Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
7. ^ a b Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
8. ^ a b c Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press
9. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins