adjective
callous
Emotionally hardened and insensitive
Where it comes from
Callous came through Middle English from Latin callosus, thick-skinned or hardened, based on callum or callus, hard skin. The noun callus and adjective callous therefore share one Latin source despite their different modern spellings.
How the meaning developed
Hard, thickened skin becomes less sensitive to touch. English turned that physical hardness into a moral metaphor: a mind or person repeatedly hardened against suffering could become insensitive and unsympathetic.
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Sources
Definitions adapted from Open English WordNet where applicable. License and attribution. Word-history text comes from Lexifour’s sourced social research; pages are assembled automatically, not individually fact-checked on every update.
Updated 2026-09-25. Report a correction.