adj. 25B6; adjective
he was very old and feeble : WEAK, weakly, weakened, frail, infirm, delicate, sickly, ailing, unwell, poorly, enfeebled, enervated, debilitated, incapacitated, decrepit.
a feeble argument : INEFFECTIVE, ineffectual, inadequate, unconvincing, implausible, unsatisfactory, poor, weak, flimsy.
he's too feeble to stand up to his boss : COWARDLY, craven, faint-hearted, spineless, spiritless, lily-livered; timid, timorous, fearful, unassertive, weak, ineffectual; informal wimpy, sissy, sissified, gutless, chicken; Brit. informal wet.
a feeble light : FAINT, dim, weak, pale, soft, subdued, muted.
strong, brave.