kakunto
The involuntary sudden drop of the head when dozing off, jerking awake from the movement.
💡Used for falling asleep on a train, nodding off while studying, or the classic sleepy head-drop.
電車でかくんと居眠りして目が覚めた。
I jerked awake on the train when my head suddenly drooped with sleep.
His head went ___ as he fell asleep during the meeting.
会議中に○○と頭が落ちて居眠りしてしまった。