Rendered resistant to the effects of nearby explosions; as, a hardened missile silo; hardened warhead electronics.

A plant condition created by various factors enabling it to withstand environmental stresses; contrast with succulent growth which is very vulnerable to environmental stress and damage.

Term for blast-resistant construction.

Experienced and inured to hardship; as, hardened combat troops.

Strongly habituated to a certain type of behavior, and unlikely to change; as, a hardened criminal. Usually used only of behavior perceived negatively.

made tough by habitual exposure; "hardened fishermen"; "a peasant, dark, lean-faced, wind-inured"- Robert Lynd; "our successors...may be graver, more inured and equable men"- V.S.Pritchett

Made hard, or harder, or compact; made unfeeling or callous; made obstinate or obdurate; confirmed in error or vice.

A product, such as the Adaptec RAID software core, that has been proven and improved over the course of time through extensive use by customers.

Entire shackle is heat-treated for added strength.

A fastener that has been heat treated to increase strength. Grade 5, Grade 8 and alloy steel bolts are hardened.

converted to solid form (as concrete)

off – gradually introduced to a new environment.

used of persons; emotionally hardened; "faced a case-hardened judge"