unimaginable

Etymology

It is formed from English un- + imaginable, with the negative prefix.^[2][3][4] Imaginable, recorded from about 1380 in Chaucer's translation of Boethius,^[5][2] is from Middle French imaginable and directly from Late Latin imāginābilis (“capable of being imagined”),^[2][3][5] from imāginor (“to picture to oneself”),^[3][5] the source of imagine (about 1340).^[5] The Latin verb is from imāgō (“an image, a likeness”).^[3][5]

Earliest recorded meaning

Incapable of being imagined; inconceivable: 1611, in Cotgrave's French–English dictionary.^[2][6] Etymonline dates it to the 1610s.^[3]

Semantic evolution

The meaning has stayed close to its first sense, "that cannot be imagined or conceived".^[2][4] Johnson (1755) defined it as "not to be imagined by the fancy; not to be conceived", quoting Milton's Paradise Lost ("So unimaginable as hate in heav'n").^[7] In present use it is often an intensifier for something beyond belief because of its extreme degree, as in unimaginable distances.^[6][8] In 1833 the plural noun unimaginables was used, like inexpressibles, as a euphemism for trousers.^[2] The adverb unimaginably and the noun unimaginableness are recorded from the mid 17th century.^[4]

Timeline

• c. 1380 – ymaginable, the base, in Chaucer's Boethius.^[5][2]
• 1611 – incapable of being imagined, inconceivable.^[2][6]
• mid 17th century – unimaginably and unimaginableness.^[4]
• 1833 – plural noun unimaginables, trousers, as a euphemism.^[2]

Meanings

Adjective

1. Impossible to imagine or understand; inconceivable, especially because of an extreme degree: They endured unimaginable hardships during the siege.^[6][8][2]

Word family

• unimaginably

Related words

• imagine
• imaginable
• image
• imagination
• imaginary

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e 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 c d e f Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
6. ^ a b c d Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
7. ^ 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 Collins English Dictionary (2023), Glasgow: HarperCollins