Quick Definition
ἰδέα, ας, ἡ n.f. form, outward appearance
Strong's Definition
from 1492; a sight (comparative figuratively "idea"), i.e. aspect
KJV Usage: countenance
UBS Dictionary of the Greek New Testament
noun, f. | -ας | εἶδος
58.14 · Nature, Class, Example · Appearance as an Outward Manifestation of Form
form, appearance appearance as the form of that which is seen In some languages a strictly literal translation of MAT 28:3 might be misinterpreted to mean that there was something jagged about the outline of Jesus’ appearance. The focus, of course, is upon the brightness, and therefore it may be important to translate ‘his appearance was bright like lightning.’
UBS Dictionary of the Greek New Testament © United Bible Societies, licensed CC BY-SA 4.0.
Thayer's Greek Lexicon
ἰδέα, -as, ἡ, (fr. εἶδον, ἰδεῖν), form, external appearance; aspect, look: Mt. xxviii. 3 (T Tr WH «idéa, q. v.), cf. Alberti, Observy. ad loc.; [Tdf. Proleg. p. 81]. (Grk. writ. fr. Pind. and Hdt. down; 2 Mace. iii. 16; for ΠΥ Gen. v. 3.) [Cf. Schmidt ch. 182, 3.]
Abbott-Smith Greek Lexicon
ἰδέα, -ας, ἡ, v.s. εἰδέα.
Moulton & Milligan — Vocabulary of the Greek NT
ἰδέα. See s.v. εἰδέα, and add P Oxy X. 1277} (Α.}. 255) προσκεφάλαια... Awa τῆς αὐτῆς εἰδαίας (1. ἰδέας), ‘of the same quality” (Edd.), and the magical papyrus P Lond 1217 (iii/A.D.) (=I. p. 108) ἵνα πᾶσαν εἰδέαν ἀποτελέσῃς. Note “εἰ-- for t-, as in Mt 283, and cf. the cognate forms εἶδος and εἴδωλον. ᾿Ιδέα comes from ἔξιδεσα (Boisacq, p- 220): see also s.v. ἴσος. On the AV translation ‘‘countenance” in Mt Zc. see Field Moves, p. 22. The word in MGr = “‘ thought,” ‘‘ idea.
Liddell-Scott-Jones — Greek-English Lexicon
ἰδέα (idea) — appearance. ἰδέα [ῐ], Ionic dialect ἰδέη, ἡ, (ἰδεῖν) form, ἰδέᾳ καλός [Refs 5th c.BC+]; opposed to χρῶμα, [Refs]; opposed to μέγεθος, [NT+5th c.BC+]; of the elementary shapes, ἄτομοι ἰδέαι [Refs 4th c.BC+]; of the four elements, Philistion cited in [Refs 1st c.AD+]
2. semblance, opposed to reality, γνώμην ἐξαπατῶσ᾽ ἰδέαι outward appearances cheat the mind, [Refs 6th c.BC+]
3. kind, sort, φύλλα τοιῆσδε ἰδέης [Refs 5th c.BC+]; φύσιν παρέχονται ἰδέης τοιήνδε [οἱ ποτάμιοι ἵπποι] [Refs]; ἐφρόνεον διφασίας ἰ. they conceived two modes of acting, [Refs]; τὰ ὄργι᾽ ἐστὶ τίν᾽ ἰ. ἔχοντά σο; what is their nature or fashion? [Refs 5th c.BC+]; ἑτέραν ὕμνων ἰ. [Refs 5th c.BC+]; καινὰς ἰ. εἰσφέρειν new forms of comedy, [Refs]; τίς ἰ. βουλεύματο; [Refs]; πᾶσα ἰ. θανάτου every form of death, or death in every form, [Refs 5th c.BC+]; πᾶσαν ἰδέαν πειράσαντες having tried every way, [Refs]; τῇ αὐτῇ ἰ. [Refs]; οὐκ ἐν ταῖς αὐταῖς ἰ. not in the same relations, [Refs 5th c.BC+]. into one kind of existence, [Refs 5th c.BC+]
4. especially in Rhet., etc., of literary form, ἀμφοτέραις ταῖς ἰδέαις κατεχρήσαντο πρὸς τὴν ποίησιν [Refs 5th c.BC+]; ἡ ἰαμβικὴ ἰ. [Refs 4th c.BC+]; ἡ ἐν τῷ λέγειν ἰ. [Refs 5th c.BC+]
4. b style, Πλατωνική, Δημοσθενικὴ ἰ., [Refs 5th c.AD+]
4. c a quality of style (e.g. σαφήνεια, γοργότης, etc.), [Refs 2nd c.AD+]
II. in Logic,= εἶδος, class, kind: hence, principle of classification, ἔφησθα.. μιᾷ ἰδέᾳ τά τε ἀνόσια ἀνόσια εἶναι καὶ τὰ ὅσια ὅσια [Refs 5th c.BC+]
II.2. plural in Platonic Philosophy, ideal forms, archetypes, τὰς.. ἰ. νοεῖσθαι μέν, ὁρᾶσθαι δ᾽ οὔ [Refs 5th c.BC+]
II.3. notion, idea, προάγειν τὸν ἀποκρινόμενον ἐπὶ τὴν ἰ. ἀγνοουμένου πράγματος [NT+4th c.BC+]