harden Synonyms

season temper inure desensitize crystallize freeze set fortify steel cure stiffen gel indurate brace rigidify petrify orientate stiffened stiffening numb naturalize mineralize solidify solidifying solidified ossified ossify sclerosis restrengthen reinforce refrigerate roughen strengthen tempered brutalise tighten up ice over toughen up unsympathetic harden up make stronger make callous become rigid dry out firm up tempering thicken toughened toughening toughen