gate-crash

from WordNet (r) 3.0 (2006)

gate-crash
    v 1: enter uninvited; informal; "let's crash the party!" [syn:
         {barge in}, {crash}, {gate-crash}]

from The Collaborative International Dictionary of English v.0.48

gatecrash \gate"crash`\ v. t.
   To enter uninvited into a party or other social event.

   Syn: intrude, barge in, crash, gate-crash, irrupt.
        [WordNet 1.5]