late 14c., "castrated animal" (especially a horse), also "a eunuch" (late 13c. as a surname), from Old Norse geldingr "wether; eunuch," from gelda "castrate" (see geld (v.)).
Entries linking to gelding
geld v.
"to castrate," c. 1300, from Old Norse gelda "to castrate," said in Watkins to be from Proto-Germanic *galdjan "to castrate," from PIE *ghel- (3) "to cut." Related to other words which, if the derivation is correct, indicate a general sense of "barren." Compare Old Norse geld-fe "barren sheep" and geldr (adj.) "barren, yielding no milk, dry," which yielded Middle English geld "barren" (of women and female animals); also Old High German galt "barren," said of a cow. Related: Gelded; gelding.