An ellision of "feet" and "attack." A sport where to competitors put their hands behind their backs and kick at each other below the waste. Different variations include:

Last Man Standing: The two fackers kick at each other until one facker can no longer stand. The last facker still able to stand wins.

Classic: Fack in rounds, sort of like boxing.

Fackarate: Kicking your opponent in different places scores different amounts of points. The facker with the most points at the end of the round wins the round. Best of 5 rounds.
Facking (sport)

In order to fack, you must have strong legs, ability to withstand pain, and, most importantly, a ferocious kick.
by Fackmaster Meehan June 2, 2011
Get the Facking (sport) mug.
Similar to boxing, facking involves at least two people attacking each other with only their feet. Hands must be held behind the back as is custom. Only feet may be used, no other appendage is allowed. Other than this there are no rules, feet may be used in literally any way possible.
Did you see that fack last night? No? Jimmy "clubfoot" Orweeny put his foot through John "the podiatrist" Mahan.

It's Fack (sport)
by GodFacker June 2, 2011
Get the Fack (sport) mug.