S: (n) foil, enhancer (anything that serves by contrast to call attention to another thing's good qualities) "pretty girls like plain friends as foils"
S: (n) hydrofoil, foil (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) "the fins of a fish act as hydrofoils"
S: (n) foil, transparency (picture consisting of a positive photograph or drawing on a transparent base; viewed with a projector)
S: (n) foil (a light slender flexible sword tipped by a button)
Verb
S: (v) foil (enhance by contrast) "In this picture, the figures are foiled against the background"
S: (v) thwart, queer, spoil, scotch, foil, cross, frustrate, baffle, bilk (hinder or prevent (the efforts, plans, or desires) of) "What ultimately frustrated every challenger was Ruth's amazing September surge"; "foil your opponent"
S: (v) foil (cover or back with foil) "foil mirrors"