v.tr. & refl. 1 (of a bird) tidy (the feathers or itself) with its beak. 2 (of a person) smarten or admire (oneself, one's hair, clothes, etc.). 3 (often foll. by on) congratulate or pride (oneself). preen gland a gland situated at the base of a bird's tail and producing oil used in preening. preener n.
[ ME, app. var. of earlier prune (perh. rel. to PRUNE(2)): assoc. with Sc. & dial. preen pierce, pin ]