An Etymological Dictionary of the German Language/Annotated/gelt
gelt (1.), particle. See gelten.
gelt (2.), adjective, ‘giving no milk, barren,’ from the equivalent Middle High German and Old High German galt; corresponding to Old Icelandic geldr, Old Swedish galder, which have the same sense. They are connected perhaps with Old High German galza, Middle High German galze, Old Icelandic gǫltr, ‘gelded pig’ (English dialectic, gilt, ilt). The stem on which it is based, gald, galt (from pre-Teutonic ghalt, ghaltn-), perhaps meant originally ‘to castrate’; compare English to geld, Old Icelandic gelda, ‘to geld’; akin to Gothic gilþa, ‘sickle’?.