noun
sleeved quilt; futon with sleeves; cotton padded nightwear
A traditional Japanese padded garment worn like a kimono for sleeping, essentially a quilt with sleeves. Often used by children or in cold weather.
寒い夜はかいまきを着て寝ると暖かい。
On cold nights, wearing a sleeved quilt to sleep keeps you warm.
祖母が子供のためのかいまきを縫ってくれた。
My grandmother sewed a sleeved quilt for the child.
The word likely derives from 掻い (kai, a prefix meaning 'to pull over oneself') + 巻き (maki, 'wrapping'), referring to a garment that is wrapped around the body. The exact historical derivation is uncertain.