Old English lilie, from Latin lilia, plural of lilium "a lily," cognate with Greek leirion, both perhaps borrowed from a corrupted pronunciation of an eastern Mediterranean word (de Vaan compares Coptic hreri, hleli "lily"). Used in Old Testament to translate Hebrew shoshanna and in New Testament to translate Greek krinon. As an adjective, 1530s, "white, pure, lovely;" later "pale, colorless" (1580s).
Figurative of whiteness, fairness, purity. The Latin word has become the general word in languages across Europe: German lilie, Dutch lelie, Swedish lilja, French lis, Spanish lirio, Italian giglio, Polish lilija, Russian liliya. The French word is contracted from Latin lilius, a rare surviving nominative form in French. In Old French lilie (12c.) also existed. Related: Lilied; lilaceous.
The lily of the valley translates Latin lilium convallium (Vulgate), a literal rendition of the Hebrew term in Song of Solomon ii:1; in modern times the name was applied to a particular plant (Convallaria majalis) apparently first by 16c. German herbalists. Lily pad is from 1834, American English. For gild the lily see gilded.