zonk out
fall asleep fast, as when one is extremely tired
人がとても疲れているので、はやく寝入る
after the long drive, we zonked out and slept for 10 hours
長いドライブの後で私たちは疲れ果て10時間も寝た
上位語
flake out, drift off, doze off, drop off, drowse off, nod off, dope off, fall asleep