- (n.) Anything that serves by contrast of color or quality to adorn or set off another thing to advantage.
- (n.) A leaf or very thin sheet of metal; as, brass foil; tin foil; gold foil.
- (v.t.) To render (an effort or attempt) vain or nugatory; to baffle; to outwit; to balk; to frustrate; to defeat.
- (v.t.) To blunt; to dull; to spoil; as, to foil the scent in chase.
- (n.) Failure of success when on the point of attainment; defeat; frustration; miscarriage.
- (v.t.) To defile; to soil.
- (v.t.) To tread under foot; to trample.
- (n.) The space between the cusps in Gothic architecture; a rounded or leaflike ornament, in windows, niches, etc. A group of foils is called trefoil, quatrefoil, quinquefoil, etc., according to the number of arcs of which it is composed.
- (n.) A thin coat of tin, with quicksilver, laid on the back of a looking-glass, to cause reflection.
- (n.) A thin leaf of sheet copper silvered and burnished, and afterwards coated with transparent colors mixed with isinglass; -- employed by jewelers to give color or brilliancy to pastes and inferior stones.
- (n.) The track or trail of an animal.
- (n.) A blunt weapon used in fencing, resembling a smallsword in the main, but usually lighter and having a button at the point.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). foil. Retrieved September 23, 2026, from http://smartdefine.org/foil/definitions/2009092 |
| Chicago | Webster's. 2011. "foil" http://smartdefine.org/foil/definitions/2009092 (accessed September 23, 2026). |
| Harvard | Webster's 2011, foil, Smart Define, viewed 23 September, 2026, <http://smartdefine.org/foil/definitions/2009092>. |
| MLA | Webster's. "foil" 27 May 2011. Web. 23 September 2026. <http://smartdefine.org/foil/definitions/2009092> |