Quick Definition
a light, brilliancy
Strong's Definition
an illuminator, i.e. (concretely) a luminary, or (abstractly) brilliancy
Derivation: from G5457 (φῶς);
KJV Usage: light
Thayer's Greek Lexicon
φωστήρ, φωστηρος, ὁ (φῶς, φώσκω);
1. that which gives light, an illuminator (Vulg.luminar): of the stars (luminaries), Php_2:15 (Wis_13:2; Sir_43:7; Gen_1:14; Gen_1:16; Heliodorus 2, 24; (Anthol. Pal. 15, 17; of sun and moon, Test xii. Patr. test. Levi 14 ); ecclesiastical writings.)
2. light, brightness: Rev_21:11 (Anthol. 11, 359) (others refer this to 1; cf. Trench, § xlvi.).
Mounce Concise Greek Dictionary
φωστήρ phōstēr 2x
a cause of light, illuminator; a light, luminary, star, Php_2:15 ;
radiance, or, luminary, Rev_21:11
Abbott-Smith Greek Lexicon
φωστήρ , -ῆρος , ὁ
( < φῶς ),
[in LXX : Gen_1:14 ; Gen_1:16 ( H3974 ), Da LXX Dan_12:3 ( H2096 ), 1Es_8:79 , Wis_13:2 , Sir_43:7 * ;]
a luminary, light: Php_2:15 , Rev_21:11 .†
SYN.: φέγγος G5338 , φῶς G5457 .
Moulton & Milligan — Vocabulary of the Greek NT
φωστήρ [page 680]
a luminary (Php. 2:15, Rev. 21:11 : cf. Gen. 1:16) : cf. P Leid W vii. 35 (ii/iii A.D.) (=11. p. 105) δόξα τοῦ ἐντίμου φωστῆρος , Wόnsch AF p. 23 .23 (iii/A.D.) ὁρκίζω σε τὸν φωστῆρα καὶ ἄστρα ἐν οὐρανῷ ποιήσαντα , and Vett. Val. p. 110 .22 περὶ τοὺς φωστῆρας ἀδικούμενοι , where the editor understands φωστῆρες as = oculi.
Liddell-Scott — Intermediate Greek Lexicon
φωστήρ φωστηφαιλινγ ον λεμβυφ [] ´ρ, ῆρος, ὁ, [Etym: φῶς] "that which gives light, an illuminator", Anth. :— οἱ φωστῆρες "the lights of heaven, stars", id=Anth. , NTest.
STEPBible — Tyndale Abridged Greek Lexicon
φωστήρ, -ῆρος, ὁ
(φῶς), [in LXX: Gen.1:14, 16 (מָאוֹר), Dan LXX 12:3 (זֹהַר), I Est.8:79, Wis.13:2, Sir.43:7 * ;]
a luminary, light: Php.2:15, Rev.21:11.†
SYN.: φέγγος, φῶς (AS)