I looked up "Parkour" on lexicon.com and got grades for parker, parky, perkier, and porker, but not for parkour! Spell keep an eye on suggests tract our, parker, and parlor, but doesn't have parkour. I even looked it up in Merriam Webster's Collegiate Dictionary, the 11th and current edition, but it wasn't there, any. It does exist though, and its popularity is growing.
So what is it? It's a manner of elbow grease that involves thing promotion and avoiding obstacles in one's footpath by jumping, vaulting, or climb ended them. Its cause is French, but in new years, has get favourite in the United States. The founder of Parkour, David Belle, describes it as "using geographical lightness and fast reasoning to get out of baffling situations, and to be able to go anyplace that one desires."