godan verb (-su), transitive verb
be absorbed in; lose oneself in
Used when someone becomes completely engrossed in an activity or state, often to the point of neglecting appearance or surroundings. Common in the phrase やつす身 (a person who has let themselves go).
彼は研究に身をやつしている。
He is absorbed in his research.
彼
She lost herself in grief.
godan verb (-su), transitive verb
disguise oneself as; dress up as
Refers to changing one's appearance to look like someone else, often in a shabby or humble disguise. Can also mean adorning oneself in a showy way, though this usage is less common.
彼は乞食に身をやつして敵地に潜入した。
He disguised himself as a beggar and infiltrated enemy territory.
女優は派手な衣装に身をやつした。
The actress adorned herself in a flashy costume.