Callus:

[Rihanna]

1: A person who is very [uncaring] as to the feelings of others and is also very self absorbabed as is the case with Kanye West
2: A thickening of or a hard thickened area on skin or bark
3: A mass of exudate and connective tissue that forms around a break in a bone and is converted into [bone in] healing
4: The [soft tissue] that forms over a wounded or cut plant surface