look up any word, like columbusing:
 
1.
First. Outside. Inside. Last
Foil gives me great pleasure in multiplying binomials.
by Omikron October 02, 2005
 
2.
A thrusting weapon used in fencing.
He scored a point by putting the point of his foil on his opponent's torso.
by The Professor November 07, 2003
 
3.
In Australia, a foil, is a $25AUD deal of weed.
"Do you sell foil's?"
by Diego July 26, 2003
 
4.
(v.) To publicly humiliate or embarrass someone. To prove someone wrong in an embarrassing manner. Synonymous with "own" or "pwn."
HP really foiled Falc by posting his gigantic rambling love letter to her for everyone else to see on the internet.
by dantehicks3737 February 14, 2005
 
5.
Stands for First Outer Inner Last

A math acronym used for multiplying binomials.

This is known to the world as the best math operation known to man. It is by far the most useful, this is a scientifically proven FACT and should not be disputed by anyone, ever. Doing so is punishable by death.
Courtney - "Did you hear the Bobby does not like to FOIL?"
Abbey - "He should be killed, because that is punishable by death..."
by Steve Perry! January 17, 2012
 
6.
1. (v.) To publicly humiliate or embarrass someone. To prove someone wrong in an embarrassing manner. Synonymous with "own" or "pwn."
2. First. Outside. Inside. Last (A rule for binomial multiplication in mathematics.)
3. A thrusting weapon used in fencing.
4. In Australia, a foil, is a $25AUD deal of weed.
5. A $20nzd deal of marijuana wrapped in tin foil,around 10grams. Also refered to as a tinny.
1. HP really foiled Falc by posting his gigantic rambling love letter to her for everyone else to see on the internet.
2. You want a math example? Seriously? Give me a break.
3. He scored a point by putting the point of his foil on his opponent's torso.
4. "Do you sell foil's?"
5. "Yo, do you know where I can score me a foil?"
by Will the Awesome April 21, 2007
 
7.
An individual package of heroin wrapped in foil, usually of a 10$ value. Foils are sold on the street and through drug dealers. Usually yields 3 to 4 decent-sized lines, providing your dealer isn't a fuck..
"dude, I am fiending hardcore, do you have any more foils?"
by Matt December 05, 2003