Callous
Part of speech: adjective
Definition: Emotionally hardened; unfeeling and indifferent to the suffering of others. Having calluses.
Example sentence: I think the mistake lots of people make when it comes to a psychopath is that they completely write off their actions as cruel, callous and completely calculated, but actually, the truth is that they have interests and reasons behind their actions.
Thickened
Part of speech: verb
Definition: To make thicker (in the sense of wider).