godan verb (-ru), intransitive verb
get warm; become warm
Intransitive verb describing something becoming warm on its own, often used for objects, rooms, or the body. Closely related to 温まる (あたたまる), but ぬくもる has a softer, more gradual or cozy nuance.
See also: 温まる
ストーブで部屋がぬくもってきた。
The room has gotten warm from the heater.
手がだんだんぬくもってきた。
My hands gradually became warm.