The Collaborative International Dictionary of English v.0.48:

Entrap \En*trap"\, v. t. [imp. & p. p. Entrapped; p. pr. & vb.
   n. Entrapping.] [Pref. en- + trap: cf. OF. entraper.]
   To catch in a trap; to insnare; hence, to catch, as in a
   trap, by artifices; to involve in difficulties or distresses;
   to catch or involve in contradictions; as, to be entrapped by
   the devices of evil men.
   [1913 Webster]

         A golden mesh, to entrap the hearts of men. --Shak.

   Syn: To insnare; inveigle; tangle; decoy; entangle.
        [1913 Webster]

WordNet (r) 3.0 (2006):

entrap
    v 1: take or catch as if in a snare or trap; "I was set up!";
         "The innocent man was framed by the police" [syn:
         ensnare, entrap, frame, set up]
    2: catch in or as if in a trap; "The men trap foxes" [syn:
       trap, entrap, snare, ensnare, trammel]

Moby Thesaurus II by Grady Ward, 1.0:

69 Moby Thesaurus words for "entrap":
   allure, bag, bait, bait the hook, birdlime, burden, catch,
   catch out, catch up, cramp, cripple, cumber, decoy, embarrass,
   encumber, enmesh, ensnare, ensnarl, entangle, entice, entoil,
   entrammel, entwine, enweb, fetter, foul, gin, hamper, hamstring,
   handicap, harpoon, hobble, hook, hook in, impede, inveigle,
   involve, lame, land, lasso, lead, lime, lumber, lure, mesh, nail,
   net, noose, press down, rope, sack, saddle with, shackle, snag,
   snare, snarl, sniggle, spear, spread the toils, take, tangle,
   tangle up with, toil, toll, trammel, trap, trip, weigh down,
   wind