The Collaborative International Dictionary of English v.0.48:

Enervate \E*ner"vate\, v. t. [imp. & p. p. Enervated; p. pr. &
   vb. n. Enervating.] [L. enervatus, p. p. of enervare, fr.
   enervis nerveless, weak; e out + nervus nerve. See Nerve.]
   To deprive of nerve, force, strength, or courage; to render
   feeble or impotent; to make effeminate; to impair the moral
   powers of.
   [1913 Webster]

         A man . . . enervated by licentiousness. --Macaulay.
   [1913 Webster]

         And rhyme began t' enervate poetry.      --Dryden.

   Syn: To weaken; enfeeble; unnerve; debilitate.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Enervate \E*ner"vate\, a. [L. enervatus, p. p.]
   Weakened; weak; without strength of force. --Pope.
   [1913 Webster]

WordNet (r) 3.0 (2006):

enervate
    v 1: weaken mentally or morally
    2: disturb the composure of [syn: faze, unnerve, enervate,
       unsettle]

Moby Thesaurus II by Grady Ward, 1.0:

91 Moby Thesaurus words for "enervate":
   abate, afflict, attenuate, beat, blunt, break, burn out, castrate,
   cramp, cripple, damp, dampen, deaden, debilitate, defeat,
   demasculinize, dematerialize, derange, desex, desexualize,
   devitalize, disable, disembody, disorder, do in, do up, drain,
   dull, effeminize, emasculate, enfeeble, etherealize, etiolate,
   eviscerate, exhaust, extenuate, fag, fag out, fatigue, flag,
   frazzle, gruel, harass, hospitalize, incapacitate, indispose,
   invalid, jade, knock out, knock up, lay low, lay up, mitigate,
   overfatigue, overstrain, overtire, overweary, poop, poop out,
   prostrate, rarefy, rattle, reduce, sap, shake, shake up, sicken,
   soften up, spiritualize, sterilize, strain, subtilize, tire,
   tire out, tire to death, tucker, unbrace, undermine, unman,
   unnerve, unstrengthen, unstring, use up, weaken, wear, wear down,
   wear on, wear out, weary, wilt, wind