χαίρε ἄριστε Γαρι
The classic text on νέυω/ἀνανέυω is Iliad 1:528ff. Achilles’ mother asks Zeus to help him out by routing the Greeks while Achilles sits on the side lines. Zeus agrees by nodding his head forward:
ἦ καὶ κυανέῃσιν ἐπ’ ὀφρύσι νεῦσε Κρονίων.
ἀμβρόσια δ’ ἄρα χαῖται ἐπερρώσαντο ἄνακτος
κρατὸς ἀπ’ ἀθανάτοιο. μέγαν δ’ ἐλέλιξεν Ὄλυμπον.
I’ll translate it into Koine:
οὕτως εἶπεν ὁ υἱὸς τοῦ Κρόνου. καὶ ἔνευσεν ἐν ταῖς μελαίναις ὀφρύσιν τῶν ὀφθαλμῶν αὐτοῦ. αἱ δὲ θεῖαι τρίχαι τοῦ κυρίου ἐξέπεσαν ἐκ τῆς ἀθανάτου κεφαλῆς. ὁ δ’ Ὄλυμπος σφόδρα ἐσείθη.
Thus spoke the son of Cronus. And he nodded forward in assent with his dark eyebrows. And the divine hairs of the lord fell forth from his immortal head. And Olympus was greatly shaken.
From this we learn three things about these νεύματα.
1. They involved not only moving the head but presumably moving the eye brows.
2. They were forceful, at least the “yes” was. No slight incline of the head, but a powerful rollicking intense enough to shake buildings, at least if you were a god.
3. If you need a favor from Zeus, it helps if you have a mother who is sort of hot.