noun
one shoulder exposed
Rare term describing the state of having one shoulder bare, typically because one sleeve of a kimono is undone or slipped off. Often used in literary or historical contexts.
彼は片肌脱ぎで酒を飲んでいた。
He was drinking sake with one shoulder exposed.
肌脱ぎ means stripping to the waist or baring the upper body, while 片肌脱ぎ specifically refers to exposing only one shoulder.
Compound of 片 (kata, 'one side') + 肌 (hada, 'skin') + 脱ぎ (nugi, 'removing clothing'). The exact historical derivation is uncertain, but the word literally describes a one-sided undressing.