δίφθογγος

ον, ἡ
A. with two sounds, γραφή Tz. H. 5.694: δίφθογγος,ἡ, diphthong, D.T. 639.15, A.D. Adv. 128.8, al.: later δίφθογγον,τό, Hdn. Epim. 245.
Liddell, Scott & Jones
A Greek-English Lexicon, 1940
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