(of a bird) tidy and clean its feathers with its beak:reed buntings preened at the pool’s edge [with object]:the pigeon preened her feathers
(also preen oneself) (of a person) devote effort to making oneself look attractive and then admire one’s appearance:adolescents preening in their bedroom mirrors
(preen oneself) congratulate or pride oneself:he’s busy preening himself on acquiring such a pretty girlfriend