λάπη · lapē — LSJ
scum, with a scum on it
scum which forms on the surface of wine, vinegar, or other liquids left to stand, Erot.: λάμπη in Dsc. 5.76, Plu. Comm.not. 2.1073a, Gal. 16.704, Orib. Syn. 9.13.2:—hence λαμπῶδες, of urine, with a scum on it, Hp. Coac. 182, Prorrh. 1.92; but Erot. read λαπῶδες, and λαππώδης (ἀπὸ τοῦ λάππειν) occurs in Gal. l.c.
2 phlegm
phlegm, Hp. Morb. 2.15, Int. 12; μεστοὶ λάπης Diph. 17.15; cf. λέμφος.
3 filth, damp
metaph., ἀνηλίῳ λάπᾳ (Wieseler for λάμπᾳ) in sunless filth or damp, of the nether world, A. Eu. 387 (lyr.).