Dictionary

A very thin sheet of metal.

Thin aluminium/aluminum (or, formerly, tin) used for wrapping food.

Example: wrap the sandwich up in foil

A thin layer of metal put between a jewel and its setting to make it seem more brilliant.

(authorship) In literature, theatre/theater, etc., a character who helps emphasize the traits of the main character and who usually acts as an opponent or antagonist.

To cover or wrap with foil.

Failure when on the point of attainment; defeat; frustration; miscarriage.

One of the incorrect answers presented in a multiple-choice test.

To prevent (something) from being accomplished.

Example: I was foiled by my superior

To prevent (someone) from accomplishing something.

Example: They foiled my plans.

To blunt; to dull; to spoil.

Example: to foil the scent in hunting

To tread underfoot; to trample.

The track of an animal.

To expand a product of two or more algebraic expressions, typically binomials.

To defile; to soil.