[weak.en] vb weak.ened ; weak.en.ing vt (1530) 1: to make weak: lessen the strength of
2: to reduce in intensity or effectiveness ~ vi: to become weak -- weak.en.er n syn weaken, enfeeble, debilitate, undermine, sap, cripple, disable mean to lose or cause to lose strength or vigor. weaken may imply loss of physical strength, health, soundness, or stability or of quality, intensity, or effective power "a disease that weakens the body's defenses against infection". enfeeble implies an obvious and pitiable condition of weakness and helplessness "enfeebled by starvation". debilitate suggests a less marked or more temporary impairment of strength or vitality "the debilitating effects of surgery". undermine and sap suggest a weakening by something working surreptitiously and insidiously "a poor diet underm ines your health" "drugs had sapped his ability to think". cripple implies causing a serious loss of functioning power through damaging or removing an essential part or element "crippled by arthritis". disable suggests a usu. sudden crippling or enfeebling "disabled soldiers received an immediate discharge".