weaken

1 to diminish the physical strength of weeks of hardship in the desert had greatly weakened them Synonyms debilitate, devitalize, enervate, enfeeble, etiolate, prostrate, sap, soften, tire, waste Related Words cripple, disable, hamstring, incapacitate; deplete, depress, exhaust, impoverish, unman, wash out; damage, harm, hurt, impair, injure, invalid, lay up; break down, grind (down), wear down, wear out; paralyze Near Antonyms energize, invigorate, recruit, rejuvenate, vitalize; harden, season, toughen Antonyms beef (up), fortify, strengthen

2 to lose bodily strength or vigor the bodybuilder weakened once she eased off on her workouts Synonyms decay, droop, emaciate, fade, fail, flag, go, lag, languish, sag, sink, waste (away), wilt, wither Related Words break down, wear out; yield; degenerate, deteriorate, rot, run down Near Antonyms convalesce, rally, rebound, recover, recuperate; gain

3 to alter (something) for the worse with the addition of foreign or lower-grade substances weakened the juice with too much water Synonyms cut, dilute, extend, lace, sophisticate, thin, water down, adulterateRelated Words load; befoul, contaminate, corrupt, defile, dirty, envenom, foul, infect, poison, pollute, soil, spoil, sully, taint; cheapen, debase, degrade; manipulate, misrepresent, tamper (with); counterfeit, fake, falsify, fudge; doctor, spike; attenuate, moderate, qualify, temperNear Antonyms fertilize, lard; augment, reinforce (also reenforce), supplement; decontaminate, purify; clarify, clean, cleanse, distill (also distil), filter, flush, leach, pasteurize, purge, refine; better, enhance, improve; compact, concentrate, condenseAntonyms enrich, fortify, richen, strengthen