Meaning of multifoil

mul•ti•foil

Pronunciation: (mul'tu-foil"), [key]
— Archit. Archit.
—n.
  1. a foil, esp. one having more than five lobes.
—adj.
  1. (of an arch, window opening, etc.) having the form of a foil with more than five lobes.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.