Webster's Revised Unabridged Dictionary · 1913

Milfoil

Milfoil , noun

[French mille-feuille, Latin millefolium; mille thousand + folium leaf. See Foil a leaf.]

(Botany) A common composite herb (Achillea Millefolium) with white flowers and finely dissected leaves; yarrow.
Collocations (1)
Water milfoil (Botany) , an aquatic herb with dissected leaves (Myriophyllum).