[1] Other forms of the headword adjective neo/smhktos -- here in either the masculine accusative singular or the neuter nominative/accusative singular -- occur in Homer (Iliad 13.342), Callimachus, Euphorion, and later prose. The headword itself is perhaps quoted from Greek Anthology 6.227.2 (Crinagoras of Mytilene), though there are later possibilities: [John of Damascus], Life of Barlaam and Joasaph 296.11, and Constantine Porphyrogenitus, On ceremonies 1.2.11 (both referring to clean mirrors, so the second gloss here would be more relevant than the first).
[2] The Ambrosian Lexicon has something comparable, according to Adler.