ὑπόλισπος
From LSJ
ταυτὶ γὰρ συκοφαντεῖσθαι τὸν Ἕκτορα ὑπὸ τοῦ Ὁμήρου → that is a false charge brought against Hector by Homer
English (LSJ)
Att. ὑπόλισφος, ον,
A flat underneath, πυγίδια Ar.Eq. 1368; τὰ ὑπὸ τῷ ἰσχίῳ μήτε ὑπόλισφα ἔστω μήτ' αὖ περιττά Philostr. Gym.35; of persons, flat-hipped, Poll.2.184, Phryn.PS p.117B.; [παρθένοι] Ruf. ap. Orib.inc.2.24.
German (Pape)
[Seite 1224] etwas glatt, schlüpfrig, πυγίδια Ar. Equ. 1365.