An Etymological Dictionary of the German Language/Annotated/-aff

-aff, suffix used to form names of rivers (Erlaff, Old High German Eril-affa, Aschaff, Old High German Asc-affa), and of places (especially in Franconian and Hessian, compare Honeff), allied to which -ep, p (also Westphalian), occurs as an unchanged Low German form, e.g. in Lennep. The base *apa is Keltic (equivalent to Latin aqua, ‘water,’ Gothic ahwa, ‘river’).