To tread under foot; to trample.
- To prevent from being successful; thwart.
- To obscure or confuse (a trail or scent) so as to evade pursuers.
- Archaic A repulse; a setback.
- Archaic The trail or scent of an animal.
- A thin, flexible leaf or sheet of metal: aluminum foil.
- A thin layer of polished metal placed under a displayed gem to lend it brilliance.
- One that by contrast underscores or enhances the distinctive characteristics of another: "I am resolved my husband shall not be a rival, but a foil to me” ( Charlotte Brontë).
- The reflective metal coating on the back of a glass mirror.
- Architecture A curvilinear, often lobelike figure or space formed between the cusps of intersecting arcs, found especially in Gothic tracery and Moorish ornament.
- An airfoil.
- Nautical A hydrofoil.
- To cover or back with foil.
- To set off by contrast.
- A fencing sword having a usually circular guard and a thin, flexible four-sided blade with a button on the tip to prevent injury.
- The art or sport of fencing with such a sword. Often used in the plural: a contest at foils.