expression, godan verb (-tsu)
turn over in sleep; toss and turn
Describes physically rolling over or shifting position while lying down, especially during sleep.
夜中に何度も寝返りを打った。
I turned over many times during the night.
expression, godan verb (-tsu)
Figurative use: switching allegiance or betraying someone, often in political, business, or personal contexts.
彼は敵側に寝返りを打った。
He went over to the enemy side.