[ 'kaləs ]
(also callous )
■ noun
1》 a thickened and hardened part of the skin or soft tissue, especially one caused by friction.
2》 Medicine the bony healing tissue which forms around the ends of broken bone.
3》 Botany a hard formation of tissue, especially new tissue formed over a wound.
Origin
C16: from L. callum , ~ 'hardened skin'.