Quick Definition
ἀφυπνόω v. I fall asleep
Strong's Definition
from a compound of 575 and 5258; properly, to become awake, i.e. (by implication) to drop (off) in slumber
KJV Usage: fall asleep
UBS Dictionary of the Greek New Testament
verb | ὕπνος
23.70 · Physiological Processes and States · Sleep, Waking
to fall asleep to begin to sleep It would obviously be a mistake to try to imitate the English idiom ‘to fall asleep,’ for this might be understood as ‘to go to sleep and as a result fall down’ or even ‘to fall down and then remain unconscious.’
UBS Dictionary of the Greek New Testament © United Bible Societies, licensed CC BY-SA 4.0.
Thayer's Greek Lexicon
ἀφ-υπνόω, -ῶ: 1 aor. ἀφύπνωσα ; (ὑπνόω to put to sleep, to sleep); a. to awaken from sleep (Anthol. Pal. 9, 517, 5). b. to fail asleep, to fall off to sleep: Lk. viii. 23; for this the ancient Greeks used καθυπνόω; see Lobeck ad Phryn. p. 224. [Herm. vis. 1, 1.]
Mounce Concise Greek Dictionary
ἀφυπνόω aphypnoō 1x
to awake from sleep; in NT to go off into sleep, fall asleep, Lk. 8:23*
Abbott-Smith Greek Lexicon
**† ἀφ-υπνόω, -ῶ
(< ὑπνόω, to put to sleep), [in Al.: Ge 28:11*;]
to awake from sleep (Anth.).
= cl. καθυπνόω (MM, s.v.), to fall asleep: Lk 8:23.†
Moulton & Milligan — Vocabulary of the Greek NT
ἀφυπνόω. Plummer on Lk 833 says the use = ‘‘fall asleep” is ‘medical and late”: unfortunately he gives no evidence of the former (nor does Hobart mention it), but the citation from Heliodorus is to be noted. Lobeck P77. p. 224 gives others. The transference of an ἀπό compound from the end of an action to the beginning of it is seen also in ἄφιξις (g.v.): in neither case is Luke likely to have started the change of meaning, but our evidence is still scantier here than there.
Liddell-Scott-Jones — Greek-English Lexicon
ἀφυπνόω (aphupnoō) — to fall sleep. ἀφυπν-όω, awake from sleep, [Refs 1st c.AD+]
II. fall asleep, [NT+7th c.AD+]:—middle, [Refs 3rd c.AD+]