godan verb (-gu), intransitive verb
strip to the waist; bare one's upper body
Literally removing clothing from the upper body, often to work or fight. Can imply readiness for physical effort.
暑いので、彼は肌脱いで庭仕事をした。
Because it was hot, he stripped to the waist and did the yard work.
godan verb (-gu), intransitive verb
pitch in; lend a hand
Figurative extension: to throw oneself into a task with great effort, as if stripping down for work. Often used in the set phrase 一肌脱ぐ (ひと肌脱ぐ).
地域の祭りのために、みんなで一肌脱ごう。
Let's all pitch in for the local festival.