"royal tax in medieval England," Old English gield "payment, tribute," from Proto-Germanic *geldam "payment" (cf. Middle High German gelt "payment, contribution," German geld "money," Old Norse gjald "payment," Gothic gild "tribute, tax"), from PIE root of yield (v.).
"to castrate," c.1300, from Old Norse gelda "castrate" from geldr "barren," from Proto-Germanic *galdu-, from PIE *ghel- "to cut." Related: Gelded. Cf. Old Norse geldr "yielding no milk, dry," Old High German galt "barren," said of a cow.