From a compound of meta and a collateral form of airo or perhaps rather aer (compare "meteor"); to raise in mid-air, i.e. (figuratively) suspend (passively, fluctuate or be anxious) -- be of doubtful mind.
see GREEK meta
see GREEK airo
see GREEK aer
a. elated with hope, Diodorus 13, 46; lofty, proud, Polybius 3, 82, 2; 16, 21, 2; the Sept. Isaiah 5:15.
b. wavering in mind, unsteady, doubtful, in suspense: Polybius 21, 10, 11; Josephus, Antiquities 8, 8, 2; b. j. 4, 2, 5; Cicero, ad Att. 5, 11, 5; 15, 14; hence, μετεωρίζω);
1. properly, to raise on high (as ναῦν εἰς τό πέλαγος, to put a ship (out to sea) up upon the deep, Latinpropellere in altum, Philostr. v. Revelation 6, 12, 3 (cf. Thucydides 8, 16, 2); τό ἔρυμα, to raise fortifications, Thucydides 4, 90): ἑαυτόν, of birds, Aelian h. a. 11, 33; passive μετεωρίζεσθαι ἤ καπνόν ἤ κονιορτόν; Xenophon, Cyril 6, 3, 5; of the wind, ἄνεμος ξηρός μετεωρισθεις, Aristophanes nub. 404; and many other examples also in secular authors; in the Sept. cf. Micah 4:1; Ezekiel 10:16; Obadiah 1:4.
2. metaphorically,
a. to lift up one's soul, raise his spirits; to buoy up with hope; to inflate with pride: Polybius 26, 5, 4; 24, 3, 6 etc.; joined with φυσαν, Demosthenes, p. 169, 23; Philo, vit. Moys. i. § 35; (quis rer. div. her. § 14, 51; cong. erud. grat. § 23); passive to be elated; to take on airs, be puffed up with pride: Aristophanes av. 1447; often in Polybius; Diodorus 11, 32, 41; 16, 18 etc.; Psalm 130:1 b. by a metaphor taken front ships that are tossed about on the deep by winds and waves, to cause one to waver or fluctuate in mind, Polybius 5, 70, 10; to agitate or harass with cares to render anxious: Philo de monarch. § 6; Schol. ad Sophocles Oed. Tyr. 914; ad Euripides, Or. 1537; hence, Luke 12:29 agreeably to its connection is best explained, neither be ye anxious, or and waver not between hope and fear (A. V. neither be ye of doubtful mind (with marginal reading Or, live not in careful suspense)). Kuinoel on Luke, the passage cited discusses the word at length; and numerous examples from Philo are given in Loesner, Observations, p. 115ff