Henry George Liddell, Robert Scott, A Greek-English Lexicon

A.oyster; the proper Att. form is ὄστρειον （“ὄστρεια . . ἔλεγον οἱ ἀρχαῖοι” Ath.3.92e, cf. Moer.p.285 P. (who recommends ὀστρία [ι_] wrongly), Phot., etc.), and this is required by the metre in the earlier Poets, “κόγχοι, μύες, κὤστρεια” A.Fr.34; “ὄστρεια συμμεμυκότα” Epich.42 (ὄστρεα codd. Ath.); “πίννῃσι καὶ ὀστρείοισιν ὁμοίη” Cratin.8; “πίνναι, λεπάδες, μύες, ὄστρεια” Anaxandr.41.61 (anap.); while ὄστρεον is used in late Ep., Matro Conv.16, Nic.Fr.83, and is found in Pap., PCair.Zen.82.13 (iii B. C.), POxy.738.5 (i A. D.):—the readings vary in Pl. (v. infr. III), as in Arist., cf. HA490b10, 525a20: generally, of all bivalves, ib.525a20, 528a1, Fr.304, Gal.12.345.

II. oyster- or bivalve-shell, Arist.HA531b5, 590a32.

III. purple pigment, prob. that produced by the murex, cf. Arist.HA548a12; “ὄστρεον μόνον ἐπιφέρειν” Pl.Cra.424d; “ὀστρείῳ ἐναληλιμμένος” Id.R.420c; “τὰ σώματα ἐκέχριντο ὀστρείῳ” Callix.2: ὄστρεα: τὰ κογχύλια, Αάκωνες ἄνθος, Hsch.