foil

Definitions

• A very thin sheet of metal.
• (uncountable) 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.
• (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.
• (figuratively) Anything that acts by contrast to emphasise the characteristics of something.
• (fencing) 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.
• (heraldiccharge) A stylized flower or leaf.
• A hydrofoil.
• An aerofoil/airfoil.