Having calluses; toughened: callous skin on the elbow.
Emotionally hardened; unfeeling: a callous indifference to the suffering of others.
tr. & intr.v.cal·loused, cal·lous·ing, cal·lous·es
To make or become callous.
Origin: Middle English, from Old French cailleux, from Latin callōsus, from callum, hard skin.
Usage Note: Do not confuse the adjective callous, as in Years of dealing with criminals had left her callous, with the noun callus, as in I have a callus on my thumb. Also, do not confuse the verb callous, which means “to make or become callous,” with the verb callus “to form or develop hardened tissue.”