1. a thin sheet of metal, especially aluminum, used for wrapping or covering food
2. a person or thing that contrasts with and emphasizes the qualities of another
3. a light, flexible sword used in fencing
Usage: fencing

1. to prevent someone from succeeding in what they are trying to do

Examples

• She wrapped the leftover pizza in aluminum foil.
• The dark curtains served as a perfect foil for the bright artwork.
• His calm personality was a foil to her energetic nature.
• The fencer gripped her foil tightly before the match.
• The security system foiled the burglary attempt.
• Bad weather foiled our plans for a picnic.
• The detective managed to foil the criminal’s escape.