Foil \Foil\, n. [OE. foil leaf, OF. foil, fuil, fueil, foille, fueille, F. feuille, fr. L. folium, pl. folia; akin to Gr. ?, and perh. to E. blade. Cf. Foliage, Folio.]

1. A leaf or very thin sheet of metal; as, brass foil; tin foil; gold foil.

2. (Jewelry) 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. --Ure.

3. Anything that serves by contrast of color or quality to adorn or set off another thing to advantage.

As she a black silk cap on him began To set, for foil of his milk-white to serve. --Sir P. Sidney.

Hector has a foil to set him off. --Broome.

4. A thin coat of tin, with quicksilver, laid on the back of a looking-glass, to cause reflection.

5. (Arch.) 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.

Foil stone, an imitation of a jewel or precious stone.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Foil \Foil\, v. t. [See 6th File.]

To defile; to soil. [Obs.]

Source: Webster's Revised Unabridged Dictionary (1913)
 

Foil \Foil\, n.

1. Failure of success when on the point of attainment; defeat; frustration; miscarriage. --Milton.

Nor e'er was fate so near a foil. --Dryden.

2. A blunt weapon used in fencing, resembling a smallsword in the main, but usually lighter and having a button at the point.

Blunt as the fencer's foils, which hit, but hurt not. --Shak.

Isocrates contended with a foil against Demosthenes with a word. --Mitford.

3. The track or trail of an animal.

To run a foil,to lead astray; to puzzle; -- alluding to the habits of some animals of running back over the same track to mislead their pursuers. --Brewer.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Foil \Foil\ (foil), v. t. [imp. & p. p. Foiled (foild); p. pr. & vb. n. Foiling.]

[F. fouler to tread or trample under one's feet, to press, oppress. See Full, v. t.]

1. To tread under foot; to trample.

King Richard . . . caused the ensigns of Leopold to be pulled down and foiled under foot. --Knoless.

Whom he did all to pieces breake and foyle, In filthy durt, and left so in the loathely soyle. --Spenser.

2. To render (an effort or attempt) vain or nugatory; to baffle; to outwit; to balk; to frustrate; to defeat.

And by ? mortal man at length am foiled. --Dryden.

Her long locks that foil the painter's power. --Byron.

3. To blunt; to dull; to spoil; as, to foil the scent in chase. --Addison.

Source: Webster's Revised Unabridged Dictionary (1913)