fall asleep

Từ điển WordNet v3.1 - WordNet Dictionary

verb

change from a waking to a sleeping state (Freq. 8)
- he always falls asleep during lectures
• Syn:
dope off, flake out, drift off, nod off, drop off,
doze off, drowse off
• Ant:
wake up
• Hyponyms:
zonk out
• Verb Frames:
- Somebody ----s