The Collaborative International Dictionary of English v.0.48:

Perversion \Per*ver"sion\, n. [L. perversio: cf. F. perversion.
   See Pervert.]
   The act of perverting, or the state of being perverted; a
   turning from truth or right; a diverting from the true intent
   or object; a change to something worse; a turning or applying
   to a wrong end or use. "Violations and perversions of the
   laws." --Bacon.
   [1913 Webster]

WordNet (r) 3.0 (2006):

perversion
    n 1: a curve that reverses the direction of something; "the
         tendrils of the plant exhibited perversion"; "perversion
         also shows up in kinky telephone cords"
    2: an aberrant sexual practice; [syn: perversion, sexual
       perversion]
    3: the action of perverting something (turning it to a wrong
       use); "it was a perversion of justice"

Moby Thesaurus II by Grady Ward, 1.0:

187 Moby Thesaurus words for "perversion":
   aberrancy, aberration, abnormality, abstractionism, abuse,
   abuse of office, abuse of terms, adulteration, apparent soundness,
   befouling, befoulment, casuistry, catachresis, circularity,
   college of Laputa, coloring, confabulation, contamination,
   contorting, conversion, corrupt administration, corruption,
   debasement, debauchery, defalcation, defectiveness, defilement,
   deformation, delusion, depravity, desecration, deviance, deviancy,
   deviation, disingenuousness, distortion, diversion, eisegesis,
   embezzlement, envenoming, equivocalness, equivocation, errancy,
   erroneousness, error, evasive reasoning, exaggeration,
   expressionism, fallaciousness, fallacy, false coloring,
   false swearing, falseness, falsification, falsifying, falsity,
   fault, faultiness, festering, flaw, flawedness, fouling, garbling,
   gloss, hamartia, heresy, heterodoxy, hyperbole, illusion,
   inaccuracy, infection, injustice, insincerity, irregularity,
   jesuitism, jesuitry, kink, litotes, maladministration, malentendu,
   malfeasance, malobservation, malpractice, malversation,
   misapplication, misapprehension, misappropriation, miscitation,
   miscoloring, misconception, misconduct, misconstruction,
   misdirection, misdoing, misdrawing, misemployment, misexplanation,
   misexplication, misexposition, misfeasance, misguidance,
   mishandling, misinformation, misinstruction, misintelligence,
   misinterpretation, misjudgment, misknowledge, misleading,
   mismanagement, mispainting, misquotation, misreading, misrendering,
   misreport, misrepresentation, misstatement, misteaching,
   mistranslation, misunderstanding, misusage, misuse,
   misuse of words, mystification, nonrealism, obfuscation,
   obscurantism, obscuration, overdrawing, overstatement,
   oversubtlety, peccancy, peculation, perjury, philosophism,
   pilfering, plausibility, plausibleness, poisoning, pollution,
   poor stewardship, prevarication, profanation, prostitution,
   psychopathia sexualis, psychosexual disorder, rationalization,
   self-contradiction, sex crime, sexual abnormality, sexual deviance,
   sexual deviation, sexual pathology, sexual perversion,
   sexual psychopathy, sidetracking, sin, sinfulness, slanting,
   sophism, sophistical reasoning, sophistication, sophistry,
   special pleading, speciosity, specious reasoning, speciousness,
   squeezing, straining, subtlety, subversion, suppuration, torturing,
   twisting, understatement, unorthodoxy, untrueness, untruth,
   untruthfulness, vice, vicious circle, vicious reasoning, violation,
   vitiation, wrenching, wrong, wrongness