foil

1 archaic :  defeat

2 archaic :  the track or trail of an animal

1 :  very thin sheet metal aluminum foil

2 :  a thin piece of material (such as metal) put under an inferior or paste stone to add color or brilliance

3 :  someone or something that serves as a contrast to another acted as a foil for a comedian

4a :  an indentation between cusps in Gothic traceryb :  one of several arcs that enclose a complex figure

5 :  hydrofoil 1

1 :  to back or cover with foil

2 :  to enhance by contrast

1 :  a light fencing sword having a usually circular guard and a flexible blade of rectangular section tapering to a blunted point — compare épée, saber

2 :  the art or sport of fencing with the foil —often used in plural

:  to prevent from achieving a goal Police foiled the bank robbery.

:  a very thin sheet of metal aluminum foil

:  a fencing sword having a light flexible blade with a blunt point

:  very thin sheet metal (as of gold or platinum) used especially in filling teeth