What is the meaning of Foil?

A very thin sheet of metal.

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

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

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, but can also serve as the sidekick of the protagonist.

Anything that acts by contrast to emphasise the characteristics of something.

A very thin sword with a blunted (or foiled) tip

A thin, transparent plastic material on which marks are made and projected for the purposes of presentation. See transparency.

A premium trading card with a glossy finish.

A stylized flower or leaf.

Clipping of hydrofoil.

Clipping of aerofoil/airfoil.

To cover or wrap with foil.

Clipping of hydrofoil.

To prevent (something) from being accomplished.

To prevent (someone) from accomplishing something.

To blunt; to dull; to spoil.

To tread underfoot; to trample.

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

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

The track of an animal.

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

To defile; to soil.

A small arc in the tracery of a window, etc.

leaf (green appendage of a plant which photosynthesizes)

ring, bracelet

pigsty

Source: wiktionary.org