harden — OET · Shobdo

harden

verb

1 this glue will harden in four hours:

solidify, set, become hard, become solid, congeal, clot, coagulate, stiffen, thicken, cake, freeze, bake, crystallize;

strengthen, reinforce;

technical anneal, vulcanize, ossify, petrify;

rare indurate, inspissate, gelatinize.

▷antonyms liquefy.

2 their suffering had hardened them:

toughen, desensitize, inure, make insensitive, make tough, make unfeeling, case-harden, harden someone's heart;

deaden, numb, benumb, anaesthetize;

brutalize, make callous;

rare indurate.

▷antonyms soften.

harden Oxford Dictionary of English