noun
sleeping while standing
Colloquial term for dozing off or sleeping in a standing position, often on a crowded train or in a queue.
満員電車で立ち寝しているサラリーマンを見かけた。
I saw a businessman sleeping while standing on the crowded train.
彼は疲れていて、壁にもたれて立ち寝していた。
He was so tired that he was sleeping standing up, leaning against the wall.