ὕφᾰλ-ος · hyphal-os — LSJ
under the sea, ἔρεβος ὕ. the darkness of the deep, S. Ant. 589 (lyr.); ὕ. πέτραι AP 11.390 (Lucill.), cf. Ael. NA 14.28, Jul. Or. 1.41a; μὴ περὶ τὴν ὕφαλον (without πέτραν) ῥαγῇ τὸ σκάφος Lib. Ep. 308, cf. Id. Or. 62.32; νῆσος Luc. DMar. 10.1; τὸ ὕ. (sc. ἔδαφος), Str. 1.3.5; τὰ ὕ. τῆς νεώς the parts under water, opp. τὰ ἔξαλα, Luc. JTr. 47; ὕ. πληγή, τραύματα, damages to a ship under water, Plb. 16.3.2, 16.4.12.
metaph., secret, crafty, of men, EM 785.44; ὑ. ἡλικία καὶ μνησίκακος Gal. 19.489.
somewhat salt, ὕδατα v.l. for ὑφαλυκά, Hp. Aër. 3.