The Collaborative International Dictionary of English v.0.48:

evasion \e*va"sion\ ([-e]*v[=a]"zh[u^]n), n. [L. evasio: cf. F.
   ['e]vasion. See Evade.]
   The act of eluding or avoiding, particularly the pressure of
   an argument, accusation, charge, or interrogation; artful
   means of eluding.
   [1913 Webster]

         Thou . . . by evasions thy crime uncoverest more.
                                                  --Milton.

   Syn: Shift; subterfuge; shuffling; prevarication;
        equivocation.
        [1913 Webster]

WordNet (r) 3.0 (2006):

evasion
    n 1: a statement that is not literally false but that cleverly
         avoids an unpleasant truth [syn: evasion, equivocation]
    2: the deliberate act of failing to pay money; "his evasion of
       all his creditors"; "he was indicted for nonpayment" [syn:
       evasion, nonpayment] [ant: defrayal, defrayment,
       payment]
    3: nonperformance of something distasteful (as by deceit or
       trickery) that you are supposed to do; "his evasion of his
       clear duty was reprehensible"; "that escape from the
       consequences is possible but unattractive" [syn: evasion,
       escape, dodging]
    4: the act of physically escaping from something (an opponent or
       a pursuer or an unpleasant situation) by some adroit maneuver

Moby Thesaurus II by Grady Ward, 1.0:

142 Moby Thesaurus words for "evasion":
   abstention, airtight secrecy, anythingarianism, artifice,
   avoidance, avoiding reaction, bickering, boggling, break, breakout,
   buck-passing, captiousness, caviling, chicane, chicanery,
   circumvention, close secrecy, closeness, concealment, cop-out,
   cringe, crypticness, cunning, deceit, deception, defense mechanism,
   deliverance, delivery, discreetness, discretion, dodge, dodging,
   double-talk, duck, elusion, elusiveness, emergence, equivocating,
   equivocation, escape, escapism, eschewal, evasive action,
   evasiveness, excuse, extrication, fallback, fence-sitting, fencing,
   flight, flinch, foiling, forbearance, forestalling, forestallment,
   freeing, frustration, fudging, getaway, getting around,
   getting round, haggling, hairsplitting, hedging, hiddenness,
   hugger-mugger, hugger-muggery, impartiality, independence,
   issuance, issue, jailbreak, jink, leak, leakage, liberation,
   logic-chopping, lying, mugwumpery, mugwumpism, neutralism,
   neutrality, nit-picking, nonalignment, noncommitment,
   nonintervention, noninvolvement, nonpartisanism, nothingarianism,
   outguessing, outlet, outmaneuvering, outwitting, paltering,
   parrying, passing the buck, pettifoggery, prevarication,
   prevention, prisonbreak, pullback, pullout, pussyfooting,
   quibbling, recoil, refraining, release, rescue, retreat, riddance,
   runaround, secrecy, secretiveness, secretness, setting-free,
   shifting, shirking, shuffle, shuffling, shunning, shunting off,
   shy, sidestep, sidestepping, sidetracking, slip, sophistry,
   strict neutrality, subterfuge, suppressio veri, tergiversation,
   the dark, the runaround, the slip, thwarting, trichoschistism,
   trickery, uncommunicativeness, vent, weasel words, wince, zigzag



Bouvier's Law Dictionary, Revised 6th Ed (1856):

EVASION. A subtle device to set aside the truth, or escape the punishment of
the law; as if a man should tempt another to strike him first, in order that
he might have an opportunity of returning the blow with impunity. He is
nevertheless punishable, because he becomes himself the aggressor in such a
case. Wishard, 1 H. P. C. 81 Hawk. P. C. c. 31, Sec. 24, 25; Bac. Ab.
Fraud, A.
     2. An escape from custody.