The Collaborative International Dictionary of English v.0.48:

Infringe \In*fringe"\, v. i.
   1. To break, violate, or transgress some contract, rule, or
      law; to injure; to offend.
      [1913 Webster]

   2. To encroach; to trespass; -- followed by on or upon; as,
      to infringe upon the rights of another.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Infringe \In*fringe"\, v. t. [imp. & p. p. Infringed; p. pr. &
   vb. n. Infringing.] [L. infringere; pref. in- in + frangere
   to break. See Fraction, and cf. Infract .]
   1. To break; to violate; to transgress; to neglect to fulfill
      or obey; as, to infringe a law, right, or contract.
      [1913 Webster]

            If the first that did the edict infringe,
            Had answered for his deed.            --Shak.
      [1913 Webster]

            The peace . . . was infringed by Appius Claudius.
                                                  --Golding.
      [1913 Webster]

   2. To hinder; to destroy; as, to infringe efficacy; to
      infringe delight or power. [Obs.] --Hooker.
      [1913 Webster]

WordNet (r) 3.0 (2006):

infringe
    v 1: go against, as of rules and laws; "He ran afoul of the
         law"; "This behavior conflicts with our rules" [syn:
         conflict, run afoul, infringe, contravene]
    2: advance beyond the usual limit [syn: encroach, infringe,
       impinge]

Moby Thesaurus II by Grady Ward, 1.0:

103 Moby Thesaurus words for "infringe":
   adopt, advance upon, appropriate, arrogate, assume, barge in,
   breach, breach the law, break, break bounds, break in,
   break in upon, break the law, burst in, butt in, charge in,
   circumvent the law, come between, commit a crime, contravene, copy,
   crash, crash in, crash the gates, creep in, crowd in, cut in, defy,
   derive from, disobey, disobey the law, disregard the law,
   do violence to, edge in, elbow in, encroach, entrench, flout,
   foist in, go too far, horn in, imitate, impinge, impose, impose on,
   impose upon, infiltrate, infract, insinuate, interfere, interlope,
   interpose, intervene, intrude, invade, irrupt, know no bounds,
   make an inroad, make use of, mock, obtrude, offend, overstep,
   overstep the bounds, pirate, plagiarize, play God, press in,
   presume, pretend to, push in, put on, put upon, rush in, seize,
   set at defiance, set at naught, set naught by, simulate, slink in,
   slip in, smash in, sneak in, squeeze in, steal, steal in, storm in,
   take, take on, take over, throng in, thrust in, trample on,
   trample underfoot, trample upon, transgress, trench, trespass,
   usurp, violate, violate the law, work in, worm in