φωστήρ

ῆρος, ὁ
A. that which gives light, οἱ φ. the lights of heaven, stars, LXX Ge. 14, al., Simp. in Epict. p.72 D.; οἱ δύο φ., i.e. sun and moon, ibid., cf. Procl. Hyp. 4.72, etc.; φαίνεσθε ὡς φωστῆρες ἐν κόσμῳ Ep.Phil. 2.15.
2. splendour, radiance, ὁ φ. αὐτῆς ὅμοιος λίθῳ τιμιωτάτῳ Apoc. 21.11.
3. metaph., of a king, τῷ φ. τῷ ἡμετέρῳ Them. Or. 16.204c.
4. of the eyes, Vett.Val. 110.22.
II. opening for light, door or window, Hsch.
Liddell, Scott & Jones
A Greek-English Lexicon, 1940
An open-access project