foil - noun

a piece of thin and flexible sheet metal

anything that serves by contrast to call attention to another thing's good qualities

a device consisting of a flat or curved piece (as a metal plate) so that its surface reacts to the water it is passing through

picture consisting of a positive photograph or drawing on a transparent base; viewed with a projector

a light slender flexible sword tipped by a button

foil - verb

• enhance by contrast
• hinder or prevent (the efforts, plans, or desires) of
• cover or back with foil

foil - thesaurus

baffle   bilk   cross   enhancer   frustrate   hydrofoil   queer   scotch   spoil   thwart   transparency