Roget's Thesaurus of English Words and Phrases by Peter Mark Roget

languor, enervation; impotence &c 158; infirmity; effeminacy, feminality†; fragility, flaccidity; inactivity &c 683. anaemia, bloodlessness, deficiency of blood, poverty of blood. declension of strength, loss of strength, failure of strength; delicacy, invalidation, decrepitude, asthenia†, adynamy†, cachexy†, cachexia [Med.], sprain, strain. reed, thread, rope of sand, house of cards. softling†, weakling; infant &c 129; youth &c 127. V. be weak &c adj.; drop, crumble, give way, totter, tremble, shake, halt, limp, fade, languish, decline, flag, fail, have one leg in the grave. render weak &c adj.; weaken, enfeeble, debilitate, shake, deprive of strength, relax, enervate, eviscerate; unbrace, unnerve; cripple, unman &c (render powerless) 158; cramp, reduce, sprain, strain, blunt the edge of; dilute, impoverish; decimate; extenuate; reduce in strength, reduce the strength of; mettre de l'eau dans son vin [Fr.]. Adj. weak, feeble, debile†; impotent &c 158; relaxed, unnerved, &c v.; sapless, strengthless†, powerless; weakly, unstrung, flaccid, adynamic†, asthenic†; nervous. soft, effeminate, feminate†, womanly. frail, fragile, shattery†; flimsy, unsubstantial, insubstantial, gimcrack, gingerbread; rickety, creaky, creaking, cranky; craichy†; drooping, tottering &c v.. broken, lame, withered, shattered, shaken, crazy, shaky; palsied &c 158; decrepit. languid, poor, infirm; faint, faintish†; sickly &c (disease) 655; dull, slack, evanid†, spent, short-winded, effete; weather-beaten; decayed, rotten, worn, seedy, languishing, wasted, washy, laid low, pulled down, the worse for wear. unstrengthened &c 159 [Obs.], unsupported, unaided, unassisted; aidless†, defenseless &c 158; cantilevered (support) 215. on its last legs; weak as a child, weak as a baby, weak as a chicken, weak as a cat, weak as a rat; weak as water, weak as water gruel, weak as gingerbread, weak as milk and water; colorless &c 429. Phr. non sum qualis eram [Lat.].