From: patrick cuadrado Message: 69618 Date: 2012-05-14
> AFAIK, this *ap- is just one of the various paleo-IE 'water' roots:
> *akW-a:, *ap-/*ab-, *ip-/*ib-,*up-/*ub- studied by Villar.
may be Aks<>Ax- too, see Axona river Essone/Aisne (?) France
and Axium Itchen River (Hampshire-GB)
but may be the rapid river see Atax =At(e)- Ax <>At-aco- = Aude France = very quick