Source : Webster's Revised Unabridged Dictionary (1913)

Palpebra \Pal"pe*bra\, n.; pl. {Palpebr[ae]}. [L.] (Zo["o]l.)
   The eyelid.

Source : WordNet®

palpebra
     n : 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}]