The act of licking someone, usually their face, with tongue flattenned out in order to cover as much surface as possible in a sweeping motion. The subject, or "victim" ends up feeling - and looking, if your tongue is moist enough - like they just got licked by a large moose.
Best done when everyone has been drinking. Also should be announced beforehand if done as a game.
Hey, Bill just mooselicked Joe when he was too drunk to resist!! Gross!!