An Etymological Dictionary of the German Language/Annotated/Hippe
Hippe (1.), feminine, ‘sickle,’ a Middle German form introduced by Luther into the Modern High German literary language instead of Heppe, from Middle High German hęppe, hepe (hâppe), feminine, ‘pruning-hook’.; Old High German hęppa (hâppa), feminine, whence French happe, ‘axle-tree bed, cramp’ (from the type happia, French hache, ‘hatchet,’ is derived). Numerous South-Western dialects (Suabian also) use hâp (hôp), from Middle High German hâpe, Old High German hâppa (from Gothic *hêb-). Allied to Greek κώπη, ‘hilt, handle’?, κοπίς, ‘knife, dagger’?.
Hippe (2.), feminine, Hipplein, neuter, ‘goat,’ only in Modern High German; the more usual dialectic heppe (Bavarian, Thuringian, and Hessian) makes it probable that the word is a pet or child's term for Old German *haber, ‘he-goat’; on this point see Habergeiß and Hitte.