milfoil Meaning, Definition & Usage

  1. noun ubiquitous strong-scented mat-forming Eurasian herb of wasteland, hedgerow or pasture having narrow serrate leaves and small usually white florets; widely naturalized in North America
    yarrow; Achillea millefolium.

WordNet

Mil"foil noun
Etymology
F. mille-feuille, L. millefolium; mille thousand + folium leaf. See Foil a leaf.
Definitions
  1. (Bot.) A common composite herb (Achillea Millefolium) with white flowers and finely dissected leaves; yarrow.

Webster 1913