hardened

Short definition from Wiktionary

Verb

1. 1
   simple past and past participle of harden

Adjective

1. 1
   Having been accustomed or desensitized to something unpleasant through exposure or experience; inured.
2. 2
   Unfeeling; pitiless; callous.
3. 3
   Firmly established in a behavior seen as bad; unlikely to change one's ways; inveterate.
4. 4
   Having extra defences against attack; highly fortified.