1. Hinder or prevent (the efforts, plans, or desires) of
   "foil your opponent";
   - thwart, queer [informal], spoil, scotch, cross, frustrate, baffle, bilk [informal], scupper [informal]
    
2. Cover or back with foil
   "foil mirrors"
    
3. Enhance by contrast
   "In this picture, the figures are foiled against the background"

1. A piece of thin and flexible sheet metal
   "the photographic film was wrapped in foil"
    
2. Someone or something that enhances by providing contrast
   "pretty girls like plain friends as foils"
    
3. Picture consisting of a positive photograph or drawing on a transparent base; viewed with a projector
   "The teacher used overhead foils to display diagrams during the lecture";
   - transparency
    
4. 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 foils";
   - hydrofoil
    
5. (fencing) a light slender flexible sword tipped by a button
   "The fencer lunged forward with her foil to score a point"

Derived forms: foils, foiled, foiling

Type of: attention, contrast, counterpoint, cover, device, fencing sword, forbid, foreclose, forestall, icon, image, picture, preclude, prevent, sheet metal

Encyclopedia: Foil, Missouri