An Etymological Dictionary of the German Language/Galle
Galle (1.), f., ‘gall, bile,’ from the equiv. MidHG. galle, OHG. galla, f.; common to Teut. in the same sense (only in Goth. is the weak neu. *gallô not recorded); comp. OSax. galla, Du. gal, AS. gealla, OIc. gall, n. Like a great number of terms relating to the body (see Fuß, Herz, Niere, Nase, Ohr), Galle too has numerous correspondences in the cognate languages, which points to the antiquity of the Aryan term (Goth. *gallin- or *galzin-, from pre-Teut. ghal-); comp. Gr. χολή, χόλος, Lat. fel, fellis, n., ‘gall.’ Many etymologists connect the word with gelb (OHG. gëlo), as if gall was named from its colour; OSlov. žlŭčĭ, ‘gall’ (from *gĭlkĭ), is certainly allied to Russ. želknutĭ, ‘to turn yellow.’ Galle (2.), f., ‘barbel,’ from MidHG. galle, f., ‘swelling above the knee on the hind-leg of a horse’; comp. E. gall (swelling, sore spot, gall-nut); it is questionable whether Gall-Apfel is allied to the word. Also in Romance, Ital. galla and Span. agulla, signify ‘swelling, tumour, gall-nut.’ Hence the Lat.-Rom. galla, ‘gall-nut,’ was perhaps the source of the Teut. terms. Yet it is possible that the foreign word has been confused with a Teut. word similar in sound, especially since Swed. dialects also have a term gräsgaller, ‘swelling on the hoof of a horse.’