sound asleep Definition

asleep
adj

1. In a sleeping state.

Thesaurus: sleeping, slumbering, dozing, napping, snoozing, reposing, inert, dormant, unconscious, fast asleep, comatose, dead to the world (slang).
2. colloq
Not paying attention.
3. Said of limbs, hands, feet, etc: numb.

adverb

1. Into a sleeping state.

Example: fall asleep

Idiom: sound asleep

In a very deep sleep.

Etymology: Anglo-Saxon on slæpe.