Word Study
gatecrasher
CIDE DICTIONARY
gatecrasher, v. t.
A person who enters into a party or other social event without an invitation, or into a theater or other public performance without a ticket. [PJC]
OXFORD DICTIONARY
gatecrasher, n. an uninvited guest at a party etc.
Derivative
gatecrash v.tr. & intr.
For further exploring for "gatecrasher" in Webster Dictionary Online