Sound asleep? (5)

I believe the answer is:

'sound asleep?' is the definition.
(sound made by a sleeping person)

This is the entire clue.

(Other definitions for snore that I've seen before include "How to keep someone awake while sleeping?" , "Make noises sleeping" , "Make racous nocturnal sound" , "Breathe noisily during sleep" , "Make raucous nasal sound during sleep" .)

I've seen this clue in The Globe and Mail, the Evening Standard and The Guardian.

Want a hint initially instead of a full solution? Install my app