- made or become hard or harder.
- pitiless; unfeeling.
- firmly established or unlikely to change; inveterate: a hardened criminal.
- inured; toughened: a hardened trooper.
- rigid; unyielding: a hardened attitude.
- (of a missile base) equipped to launch missiles from underground silos.
- (of a missile) capable of being launched from an underground silo.
- rigidly set, as in a mode of behaviour
- toughened, as by custom; seasoned
- (of a nuclear missile site) constructed to withstand a nuclear attack
