Strong's G2518 — καθεύδω (verb)
katheudo (kath-yoo'-do) v.
1. to lie down to rest
2. (by implication) to fall asleep
{literally or figuratively}
[from G2596 and heudo "to sleep"]
KJV: (be a-)sleep 
Root(s): G2596 
Hebrew root: κατά
Occurrences: 22