单词 ptosis 释义 ‖ ptosis|ptss|Pl. ptoses |-iz|.[a. Gr. ῶ falling, fall.]A falling, prolapsus: a. spec. Drooping of the upper eyelid from paralysis of the elevator muscle.1743tr. Heister's Surg. (1763) I. 390 Of Relaxation and Tumor of the Eye-lids, te...