1560s (late Old English had gegylde); in modern use the more dignified past participle of gild (q.v.). Shakespeare's lilies were never gilded; the quote ("King John," iv.2) is, "To gild refined gold, to paint the lily."
Old English gyldan "to gild, to cover with a thin layer of gold," from Proto-Germanic *gulthianan (cf. Old Norse gylla "to gild," Old High German ubergulden "to cover with gold"), from *gulthan "gold" (see gold). Related: Gilded; gilding. Figuratively from 1590s.