| 词源 |
ptosis n."a falling of or inability to raise the upper eyelid," 1743, from Greek ptōsis, literally "falling, a fall," also "the case of a noun," nominal derivative of piptein "to fall" (from PIE *pi-pt-, reduplicated form of root *pet- "to rush; to fly"). In English, especially of the eyelid. Related: Ptotic. updated on January 25, 2021 |