? a kind of slippery fish, an eel (?) Only in expression amarā-vikkhepika eel-wobbler, one who practices eel-wriggling, fr. ˚vikkhepa “oscillation like the a. fish” In English idiom “a man who sits on the fence” DN.i.24; MN.i.521; Pts.i.155. The expln. given by Bdhgh at DN-a.i.115 is “amarā nāma maccha-jāti, sā ummujjana-nimmujjan-ādi vasena… gahetuṃ na sakkoti” etc. This meaning is not beyond doubt, but Kern’s expln.
71 does not help to clear it up.