The Collaborative International Dictionary of English v.0.48:

Circumvent \Cir`cum*vent"\, v. t. [imp. & p. p. Circumvented;
   p. pr. & vb. n. Circumventing.] [L. circumventis, p. p. of
   circumvenire, to come around, encompass, deceive; circum +
   venire to come, akin to E. come.]
   To gain advantage over by arts, stratagem, or deception; to
   decieve; to delude; to get around.
   [1913 Webster]

         I circumvented whom I could not gain.    --Dryden.
   [1913 Webster]

WordNet (r) 3.0 (2006):

circumvent
    v 1: surround so as to force to give up; "The Turks besieged
         Vienna" [syn: besiege, beleaguer, surround, hem in,
         circumvent]
    2: beat through cleverness and wit; "I beat the traffic"; "She
       outfoxed her competitors" [syn: outwit, overreach,
       outsmart, outfox, beat, circumvent]
    3: avoid or try to avoid fulfilling, answering, or performing
       (duties, questions, or issues); "He dodged the issue"; "she
       skirted the problem"; "They tend to evade their
       responsibilities"; "he evaded the questions skillfully" [syn:
       hedge, fudge, evade, put off, circumvent, parry,
       elude, skirt, dodge, duck, sidestep]

Moby Thesaurus II by Grady Ward, 1.0:

137 Moby Thesaurus words for "circumvent":
   avoid, baffle, balk, bamboozle, beat, befool, beg, beguile, betray,
   bilk, blast, bluff, brave, burke, bypass, cajole, challenge,
   cheat on, checkmate, circle, circuit, circuiteer, circulate,
   circumambulate, circummigrate, circumnavigate, close the circle,
   come full circle, compass, confound, confront, conjure, contravene,
   counter, counteract, countermand, counterwork, cross, cycle, dash,
   deceive, defeat, defy, delude, describe a circle, destroy, detour,
   diddle, disappoint, discomfit, disconcert, discountenance, dish,
   disrupt, ditch, double, double-cross, dupe, elude, encircle,
   encompass, escape, evade, flank, flummox, foil, forestall,
   frustrate, gammon, get around, get away from, get out of,
   get round, girdle, girdle the globe, give the runaround,
   give the slip, go about, go around, go one better, go round,
   go the round, gull, gyre, hoax, hocus-pocus, hoodwink, hornswaggle,
   humbug, juggle, knock the chocks, lap, let down, make a circuit,
   mock, nonplus, orbit, outfigure, outflank, outgeneral, outguess,
   outmaneuver, outplay, outreach, outsmart, outwit, overreach,
   pass the buck, perplex, pigeon, play one false, put something over,
   revolve, round, ruin, sabotage, scotch, shake, shake off,
   shuffle out of, sidestep, skirt, snow, spike, spiral, spoil,
   stonewall, string along, stump, surround, take in, thwart, trick,
   two-time, upset, victimize, wheel