wormwood (n.)

c. 1400, folk etymology of Old English wermod "wormwood, absinthe," related to vermouth, but the ultimate etymology is unknown. Compare Old Saxon wermoda, Dutch wermoet, Old High German werimuota, German Wermut. Weekley suggests wer "man" + mod "courage," from its early use as an aphrodisiac. Figurative use, however, is usually in reference to its proverbial bitter aftertaste. Perhaps because of the folk etymology, it formerly was used to protect clothes and bedding from moths and fleas. "A medecyne for an hawke that hath mites. Take the Iuce of wormewode and put it ther thay be and thei shall dye." ["Book of St. Albans," 1486]