Calloused means hardened by rubbing, as working hands become. Calloused palms, calloused fingers, hands calloused by work.
The hardening is protective — guitarists and climbers build them on purpose, and losing them after a break means starting over. The spelling callused is also used. Callous with no -ed is a different word meaning unfeeling, and it comes from the same hard skin.
1adjectivecallousedHardened by rubbing.
“Years of farm work had left his hands rough and calloused.”
calloused is a quality of skin.
Also accepted in games: callused
Latin
callōsus — hard-skinned
English
callous
English, today
calloused
Built from
From callous + -ed. callous comes from Latin callōsus (“hard-skinned”), from callum (“hardened skin”) + -ōsus.
Etymology from Wiktionary, CC BY-SA