ὑφέν · hyphen — LSJ
in one, as a single word, in one and the same word?
in one, as a single word, ἀναγιγνώσκειν ὑφʼ ἕν Plu. Aud.poet. 2.31e; πῶς . . πληθυντικὸν καὶ ἑνικὸν ὑφʼ ἓν κεκλήσεται; how can a plural and a singular be addressed in one and the same word? A.D. Pron. 22.7.
2 hyphen
ἡ ὑφέν the hyphen, a sign (n͜n) written below two consecutive letters to show that they belong to the same word, D.T. Supp. 674.4, Sch.D.T.p.126H., Diom.p.434 K., PAmh. 2.21.6 (iii/iv A. D.).