Indurate
Part of speech: adjective
Definition: Indurated, obstinate, unfeeling, callous.
Part of speech: verb
Definition: to harden or to grow hard to make callous or unfeeling
Callous
Part of speech: adjective
Definition: Emotionally hardened; unfeeling and indifferent to the suffering of others.Having calluses.
Example sentence: Memory in youth is active and easily impressible; in old age it is comparatively callous to new impressions, but still retains vividly those of earlier years.