Merriam-Webster's Collegiate® Dictionary, 11th Edition
ASLEEP
I. adjective
Etymology: Middle English aslepe, from Old English on slæpe
Date: 13th century
being in a state of sleep, dead , lacking sensation ; numb ,
4. inactive , dormant , not alert ; indifferent ,
II. adverb
Date: 13th century
into a state of sleep, into the sleep of death, into a state of inactivity, sluggishness, or indifference