An Etymological Dictionary of the German Language/Annotated/Geiß
Geiß, feminine, ‘goat, roe,’ from the equivalent Middle High German and Old High German geiȥ, f,; corresponding to Gothic gaits, Old Icelandic geit, Anglo-Saxon gât, English goat, Dutch geit; also a diminutive Gothic gaitein, Anglo-Saxon gœ̂ten, Old High German geizzîn, neuter, ‘kid’ (see Schwein). Primit. allied to Latin haedus from older ghaido-s (see Ritze and Ziege). In common with Slavonic, Old Teutonic has a different word for Ziege; compare Middle Dutch hoekijn, Anglo-Saxon hêcen, ‘kid,’ akin to Old Slovenian koza, ‘goat.’