indurate

From Dictionary.com

indurate \IN-dur-it; -dyur-\, adjective:
Physically or morally hardened; unfeeling; stubborn.

\IN-dur-ayt; -dyur-\, transitive verb:
1. To make hard; to harden.
2. To harden against; to make hardy; to habituate.
3. To make hardened; to make callous or stubborn.
4. To establish; to fix firmly.

intransitive verb:
1. To grow hard; to harden.
2. To become established or fixed.

Indurate is derived from the past participle of Latin indurare, from in-, intensive prefix + durare, "to harden," from durus, "hard."