The Collaborative International Dictionary of English v.0.48:

Taint \Taint\, v. i. [imp. & p. p. Tainted; p. pr. & vb. n.
   Tainting.]
   To thrust ineffectually with a lance. [Obs.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

tainted
    adj 1: touched by rot or decay; "tainted bacon"; "`corrupt' is
           archaic" [syn: corrupt, tainted]

Moby Thesaurus II by Grady Ward, 1.0:

98 Moby Thesaurus words for "tainted":
   abandoned, bad, bad for, bedraggled, befouled, besmirched,
   blackened, blown, cankered, contaminated, corrupt, corrupted,
   darkened, debased, debauched, decadent, defiled, degenerate,
   degraded, depraved, dirtied, discolored, diseased, dissolute,
   drabbled, draggled, foul, fouled, foxed, foxy, frowy, gamy,
   gangrened, gangrenous, harmful, high, impure, indecent, infected,
   injurious, inky, insalubrious, insanitary, maculate,
   morally polluted, morbid, morbific, mortified, murky, noisome,
   noxious, off, pathogenic, pathological, peccant, perverted,
   pestiferous, poisoned, polluted, profligate, rancid, rank, reechy,
   reprobate, rotten, septic, smirched, smoky, smudged, soiled, sour,
   soured, sphacelated, spotted, stained, stale, steeped in iniquity,
   stigmatic, stigmatiferous, stigmatized, strong, sullied, tarnished,
   turned, ulcerated, ulcerous, unchaste, unclean, unhealthful,
   unhealthy, unhygienic, unsanitary, unvirginal, unvirtuous,
   unwholesome, vice-corrupted, vitiated, warped