Mil"foil (?), n. [F. mille-feuille, L. millefolium; mille thousand + folium leaf. See Foil a leaf.] Bot.
A common composite herb (Achillea Millefolium) with white flowers and finely dissected leaves; yarrow.
Water milfoil Bot., an aquatic herb with dissected leaves (Myriophyllum).
© Webster 1913.