1) Acclimated 2) Accustomed 3) Accustomed to 4) Accustomed to adapted 5) Adapted to rigors 6) Case-hardened 7) Conditioned 8) Enured 9) Got used to being ruined 10) Habituated 11) Habituated in rude usage 12) Hardened 13) Hardened against 14) Hardened to 15) Having built character 16) Steeled against Found on https://www.crosswordclues.com/clue/inured