harden

1 to become physically firm or solid <the glue begins to harden as soon as it is exposed to air> Synonyms concrete, congeal, firm (up), freeze, indurate, set, solidify Related Words cake, callus, encrust (also incrust); clot, coagulate, gel, gelate, gelatinize, jell, jelly, stiffen, thicken; calcify, crystallize (also crystalize), ossify, petrify, rigidify; anneal, case-harden, temper Near Antonyms deliquesce, dissolve, flux, fuse, melt, smelt, thaw, unfreeze Antonyms liquefy (also liquify), soften

2 to make able to withstand physical hardship, strain, or exposure <pioneer women who had been hardened by years of living on the plains> Synonyms fortify, indurate, inure, season, steel, strengthen, toughen Related Words acclimate, acclimatize, adapt, adjust; anneal, temper; invigorate, vitalize; immunize; bolster, boost, brace, buttress, enforce, forearm, prop (up), reinforce (also reenforce), support; break in, limber (up), train; accustom, condition, habituate, naturalize Near Antonyms emasculate, enervate, enfeeble, exhaust, sap, weaken; cripple, debilitate, hamstring, incapacitate; sensitize Antonyms soften

3 to increase the ability of (as a muscle) to exert physical force <arm muscles that were hardened by all the years of casting and hauling his fishing nets> Synonyms beef (up), fortify, strengthen, toughenRelated Words anneal, temper; firm (up), tone (up); energize, invigorate, vitalize; restrengthenNear Antonyms cripple, incapacitate, paralyze; damage, harm, hurt, impair, injure; break down, wear out; sap, undercut, undermineAntonyms debilitate, enervate, enfeeble, weaken

4 to make more harsh, uncompromising, or severe <the government hardened restrictions on travel to and from the war-torn nation> Synonyms harshen, stiffen, strengthen, toughenNear Antonyms lessen, moderate, softenAntonyms ameliorate, ease