The Collaborative International Dictionary of English v.0.48:
Eyelid \Eye`lid"\, n. (Anat.) The cover of the eye; that portion of movable skin with which an animal covers or uncovers the eyeball at pleasure. [1913 Webster]WordNet (r) 3.0 (2006):
eyelid n 1: either of two folds of skin that can be moved to cover or open the eye; "his lids would stay open no longer" [syn: eyelid, lid, palpebra]