The verb callous has 1 sense (no senses from tagged texts)
1. callous, cauterize, cauterise -- (make insensitive or callous; deaden feelings or morals)
Overview of adj callous
The adj callous has 2 senses (first 1 from tagged texts)
1. (3) callous, indurate, pachydermatous -- (emotionally hardened; "a callous indifference to suffering"; "cold-blooded and indurate to public opinion")
2. calloused, callous, thickened -- (having calluses; having skin made tough and thick through wear; "calloused skin"; "with a workman's callous hands")