Same entry, according to Adler, in the Ambrosian Lexicon. The headword in either form is not otherwise attested. (Bernhardy refers to DuCagne's dictionary of Early Modern Greek, but that definition cites only the Suda.)
The term is presumably unrelated to kw/ph (Doric kw/pa) "handle" (kappa 2295, and cf. kappa 2296), especially "handle of oar, oar". The accentuation kw=pa appears in Orion [Author, Myth], Etymologicum s.v. and scholia to Basilica 15.1(Pi).3, but in both cases clearly refers to oars.