If someone gatecrashes a party or other social event, they go to it, even though they have not been invited. Scores of people tried desperately to gatecrash the party He had gatecrashed but he was with other people we knew and there was no problem. + gatecrasher gatecrashers gate·crash·er Panic set in as gatecrashers tried to force their way through the narrow doors and corridors. to go to a party that you have not been invited to
to go to a social event to which you are not invited, or for which you have not paid