The Collaborative International Dictionary of English v.0.48:

Unnerved \Unnerved\
   See nerved.

WordNet (r) 3.0 (2006):

unnerved
    adj 1: deprived of courage and strength; "the steeplejack,
           exhausted and unnerved, couldn't hold on to his dangerous
           perch much longer"

Moby Thesaurus II by Grady Ward, 1.0:

101 Moby Thesaurus words for "unnerved":
   aghast, anemic, appalled, ashen, asthenic, astounded, awed,
   awestricken, awestruck, blanched, bloodless, castrated, chicken,
   cowardly, cowed, crushed, dashed, deadly pale, debilitated,
   demasculinized, demoralized, devitalized, drooping, droopy, dull,
   effeminized, effete, emasculate, emasculated, enervated, etiolated,
   eunuchized, faint, faintish, feeble, flabby, flaccid, floppy,
   frozen, gelded, gone, gray with fear, gutless, horrified,
   horror-struck, imbecile, impotent, intimidated, languid,
   languorous, limber, limp, listless, lustless, marrowless,
   nerveless, neurasthenic, overcome, pale as death, pallid,
   paralyzed, petrified, pithless, pooped, powerless, prostrate,
   prostrated, reduced to jelly, rubbery, sapless, scared stiff,
   scared to death, shaken, shot, shot to pieces, sinewless, slack,
   soft, spineless, strengthless, stricken, stunned, stupefied,
   terrified, terror-crazed, terror-haunted, terror-ridden,
   terror-riven, terror-shaken, terror-smitten, terror-struck,
   terror-troubled, undone, unglued, unhardened, unmanned, unsexed,
   unstrung, upset, weak, weakly