Laudator Temporis Acti

Liddell and Scott say that ἀφυπνόω (aphypnóō) means both awake from sleep and fall asleep. If so, it would be a neat auto-antonym.

For the supposed meaning awake from sleep, see the Palatine Anthology 9.517.5-6 (epigram on Glaphyrus, a piper, tr. A.S.F. Gow and D.L. Page, who adopt a conjecture by Eldick):

ἀφυπνώσαι κεν ἀκούων / αὐτὸς Πασιθέης Ὕπνος ἐν ἀγκαλίσιν.

Sleep himself, in Pasithea's arms, would wake up when he heard you.

Gow and Page in their commentary write:

Eldick's restoration of the text seems reasonably secure but since ἀφυπνόω means both fall asleep and wake up editors have interpreted it differently. Eldick himself, Grotius, and Dübner prefer the former meaning; Jacobs, Paton, and Beckby rightly prefer the latter. They have not however noticed that with Ὕπνος as subject the verb must mean more than wake up. Sleep would renounce his name may perhaps represent the sense, which, in view of the frequent use of εὕδειν and καθεύδειν in such contexts, may imply forget his conjugal functions.

I wonder, however, about independent evidence for the meaning awake from sleep. Liddell and Scott provide only one other citation for this meaning -- Antonius Diogenes 9 (unavailable to me). Depending on the tune, piping could either put one to sleep or rouse one.

For the unmistakable meaning fall asleep, see Luke 8.23:

πλεόντων δὲ αὐτῶν ἀφύπνωσεν. καὶ κατέβη λαῖλαψ ἀνέμου εἰς τὴν λίμνην, καὶ συνεπληροῦντο καὶ ἐκινδύνευον. προσελθόντες δὲ διήγειραν αὐτὸν λέγοντες Ἐπιστάτα ἐπιστάτα, ἀπολλύμεθα: ὁ δὲ διεγερθεὶς ἐπετίμησεν τῷ ἀνέμῳ καὶ τῷ κλύδωνι τοῦ ὕδατος, καὶ ἐπαύσαντο, καὶ ἐγένετο γαλήνη.

But as they sailed he fell asleep: and there came down a storm of wind on the lake; and they were filled with water, and were in jeopardy. And they came to him, and awoke him, saying, Master, master, we perish. Then he arose, and rebuked the wind and the raging of the water: and they ceased, and there was a calm.