The Collaborative International Dictionary of English v.0.48:
lap up \lap up\, v. t. [See lap, v. i.] 1. To take up (drink or food) with the tongue; to drink by licking up. [1913 Webster] 2. (fig.) To accept or enjoy enthusiatically and uncritically; as, to lap up praise. [PJC]WordNet (r) 3.0 (2006):
lap up v 1: take up with the tongue; "The cat lapped up the milk"; "the cub licked the milk from its mother's breast" [syn: lap, lap up, lick]