Quick Definition
μεγαλεῖος, εία, εῖον Adj grand, magnificent
Strong's Definition
from 3173; magnificent, i.e. (neuter, plural as noun) a conspicuous favor, or (subjectively) perfection
KJV Usage: great things, wonderful works
UBS Dictionary of the Greek New Testament
adjc. | -α, -ον | μεγαλύνω
76.8 · Power, Force
mighty act, great deed a deed of importance and power In some contexts it is not possible to distinguish readily between τέρας[b] (76.7), δύναμις[c] (76.7), and μεγαλεῖον, for all may refer to miraculous events, and in a number of instances these terms are used in pairs, primarily to emphasize rather than to distinguish different kinds of miraculous events. All of these expressions may indicate a supernatural component with important religious implications, especially since the performance of such miracles implies divine power.
UBS Dictionary of the Greek New Testament © United Bible Societies, licensed CC BY-SA 4.0.
Thayer's Greek Lexicon
μεγαλεῖος, -εία, -eiov, (μέγας), magnificent, excellent, splendid, wonderful, (Xen., Joseph., Artem., al.); absol. peγαλεῖα (ποιεῖν τινι) to do great things for one (show him conspicuous favors), Lk. 1. 49 RG; τὰ μεγαλεῖα τοῦ θεοῦ (Vulg. magnalia dei [A. V. the mighty works of God}), i. e. the glorious perfections of God and his marvellous doings (ΠΥ 712, Ps. Ixx. (Ixxi.) 19; Sir. xxxiii. (xxxvi.) 10; xlii. 21), Acts ii. 11.
Mounce Concise Greek Dictionary
μεγαλεῖος megaleios 1x
magnificent, splendid; τὰ μεγαλεῖα, great things, wonderful works, Acts 2:11*
Abbott-Smith Greek Lexicon
μεγαλεῖος, -εία, -εῖον
(< μέγας), [in LXX: Ps 70 (71):19 (גָּדוֹל), al., freq. in Sir;]
magnificent, splendid (Xen., Plut., al.): Ac 2:11.†
Moulton & Milligan — Vocabulary of the Greek NT
μεγαλεῖος. Syll 365 (=% 798) (A.D. 37) αὐτοῦ τὸ μεγαλεῖον τῆς ἀθανασίας ---νν! ἢ reference to Caesar Germanicus. For μεγαλεῖον as a ceremonial title see further P Oxy IX. 1204?° (A.D. 299) τὸ μεγαλεῖον αὐτοῦ, ‘his highness,’’ P Amh II. 8215 (iii/iv A.D.) δι᾿ ὅπερ κ[ατέφυ]γον ἐπὶ τὸ σὸν μεγα[λεῖον —a Prefect, P Oxy I. 715 (a.p. 303) ὅθεν καὶ αὐτὴ | πρόσειμ[ι τῷ σῷ] peyarelw εὔελπις οὖσα τῆς ἀπὸ σοῦ βοηθείας τυχεῖν, ‘therefore I myself (a widow whose affairs had been mismanaged by dishonest overseers) make petition to your highness in the full confidence that I shall obtain assistance from you” (Edd.), and P Thead τοῦ (iv/A.D.) τοὺς ἀδικουμένους ὀρφανο[ύς], ἡγεμὼν δέσποτα, ἐκδικεῖν εἴωθεν τὸ μεγαλεῖον τὸ σόν. In P Lond V. 170 8529 (4.p. 567?) the plur. is used = ‘‘gospels’’—ékaorou τούτων ἐνωμότως (‘ton oath”) θεμένου ὅρκον ἐπάνω τῶν σεπτῶν (‘august ’’) μεγαλίων. For the adv. see Aristeas 20 μεγαλείως χρησάμενος TH προθυμίᾳ.
Liddell-Scott-Jones — Greek-English Lexicon
μεγαλεῖος (megaleios) — mighty. μεγᾰλεῖ-ος, α, ον, (μέγας) magnificent, splendid, ῥήματα [Refs 5th c.BC+]; κτῆμα[Refs 5th c.BC+]; πίστιν -οτάταν probably in Paean cited in [Refs 1st c.AD+]; τὸ μ. τῶν πράξεων, τῆς ἀθανασίας, [Refs 2nd c.BC+], cf. Vett. Val.70.1; τὰ μ. mighty works, [LXX+NT]. adverb -ως greatly, ὠφελῶν τὴν πόλιν [Refs 5th c.BC+]; magnificently, μ. εἴρηκας [Refs 5th c.BC+]: comparative -ότερον [Refs 5th c.BC+]; -οτέρως, γαμεῖν [Refs 5th c.BC+]
2. of persons, stately, haughty, [Refs]
3. τὸ μ. τινός, as a title, Highness, [Refs 3rd c.AD+]
4. of style, elevated, [Refs 4th c.BC+] adverb superlative -ότατα, ἑρμηνεῦσαι [Refs 2nd c.AD+]