What is the meaning of hardened?

verb

• Become hard or harder.
  • usage: "The wax hardened"
  • synonyms: harden, indurate
• Make hard or harder.
  • usage: "The cold hardened the butter"
  • synonyms: harden, indurate
• Harden by reheating and cooling in oil.
  • usage: "temper steel"
  • synonyms: temper, harden
• Make fit.
  • usage: "This trip will season even the hardiest traveller"
  • synonyms: season, harden
• Cause to accept or become hardened to; habituate.
  • usage: "He was inured to the cold"
  • synonyms: inure, harden, indurate

adjective

• Used of persons; emotionally hardened.
  • usage: "faced a case-hardened judge"
  • synonyms: case-hardened, hard-boiled
• Made hard or flexible or resilient especially by heat treatment.
  • usage: "a sword of tempered steel"; "tempered glass"
  • synonyms: tempered, treated, toughened
• Protected against attack (especially by nuclear weapons. )
  • usage: "hardened missile silos"
• 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
  • synonyms: enured, inured
• Converted to solid form (as concrete. ).
  • synonyms: set