ὑποφθέγγομαι · hypophthengomai — LSJ
speak in an undertone, hint gently, suggest
speak in an undertone, ἐντὸς ὑ., of an ἐγγαστρίμυθος, Pl. Sph. 252c; ἡσυχῇ, ἠρέμα ὑ., Luc. Nigr. 13, Longus 1.25; ὑ. τινί τι hint gently, suggest, Plu. Util. 2.88c.
2 reply
reply, τινι Id. Brut. 36.
3 speak from underground
speak from underground, J. BJ 3.2.3.
II
of birds, Ael. NA 7.7, Longus 3.12; of a dog, Plu. Arat. 8, Gal. 18(1).291; also ὑ. κερκίς Philostr. Im. 2.28.