callous

Etymology

It is borrowed from Latin callōsus (“hard-skinned, tough”),^{[2][3][4][5][6]} which Barnhart, Hoad and Merriam-Webster say was partly borrowed from Middle French calleux;^{[7][8][9][10]} the American Heritage Dictionary gives Old French cailleux as the source.^[11] The Latin adjective is formed from callum (“hardened skin”), also written callus and the source of callus, and -ōsus;^[2][3][7][6] in post-classical Latin it also meant obstinate.^[2] It gave Spanish calloso, Italian calloso and Portuguese caloso as well.^[2] Barnhart traces the Latin noun to Proto-Indo-European *kal- and compares Old Irish calath (“hard”),^[7][9] but Etymonline calls the Indo-European source uncertain.^[3]

Earliest recorded meaning

Of animal tissue, hardened and thickened: before 1400, in a translation of Lanfranc's Science of Cirurgie.^[2] Etymonline dates it to about 1400, and Barnhart to before 1400.^[3][7]

Semantic evolution

The figurative sense, not easily moved, hard and unfeeling, is recorded from 1647;^[2] Barnhart dates it to 1679 and Etymonline to the 1670s.^[7][3] The Oxford Dictionary of Word Origins compares the same transfer in thick-skinned.^[12] In later use it came to mean especially showing no regard for the feelings or welfare of others.^[2] Johnson (1755) gave both senses, "indurated" from surgery and "hardened; insensible".^[13] A botanical sense, of plant tissue harder than the tissue around it, followed in 1721,^[2] and the verb, to make the feelings hard, in 1769, at first in to callous over.^[2]

Timeline

• before 1400 – of skin or tissue, hardened and thickened.^[2][7]
• 1647 – figurative, unfeeling, not easily moved.^[2] Barnhart dates this sense to 1679.^[7]
• 1721 – in botany, of plant tissue harder than the tissue around it.^[2]
• 1769 – verb, to callous over, to harden the feelings.^[2]
• 1792 – verb, to make a person unfeeling.^[2] Merriam-Webster dates the verb to 1834.^[9]

Meanings

Adjective

1. Showing no sympathy for the suffering of others; unfeeling or heartless: a callous joke about the flood victims.^[14][9][2]
2. Of skin, hardened and thickened; having calluses.^[14][9][2]
3. (botany) Of plant tissue, harder or thicker than the tissue around it.^[2][9]

Verb

1. To make or become callous.^[14][9][2]

Word family

• callously
• callousness
• uncallous
• callosity

Related words

• callus

Usage notes

Merriam-Webster records callous also as a spelling of the noun callus, altered under the influence of the adjective,^[9] and Dictionary.com lists the two words as easily confused.^[5]

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 r 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. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., 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 Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
7. ^ a b c d e f g Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
8. ^ Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
9. ^ a b c d e f g h Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
10. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
11. ^ The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
12. ^ Cresswell, Julia (2021), Oxford Dictionary of Word Origins, 3rd ed., Oxford: Oxford University Press
13. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
14. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins