cal·lous 
(kăləs)
(kăləs)adj.
1. Having calluses; toughened: callous skin on the elbow.
2. 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.
[Middle English, from Old French cailleux, from Latin callōsus, from callum, hard skin.]
callous·ly adv.
callous·ness n.
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."