1. Used of persons; emotionally hardened
   "faced a case-hardened judge"
   - hardened, hard-boiled

1. To subject to a process which converts the surface of iron into steel 
2. To render insensible to good influences

See also: hard

• true marmoset
• true north
• true pepper
• true pine
• true puffball
• true rib
• true sago palm
• true sandalwood
• true seal
• true senna
• true slime mold
• true slime mould
• true sparrow
• true statement
• true to
• true to life
• true toad
• true tulipwood
• true up
• true vampire bat
• true vocal cord
• true vocal fold
• true warbler
• true-blue
• true-false