Basically means to rule over another person, or to get told/killed(in fps and MMO)/raped/etc. Commonly used now and is a common trend amongst most people to say it.
Pwnage is pronounced "OWN" and usually people spell Pwn as Own. People also pronounce it incorrectly as "Porn" and "Poan".
Present tense: PWN (I pwn all ur asses)
Past tense: PWNED (YOU GOT PWNED !!!111oneoneone)
Adjective: PWNAGE (Fear my PWNAGE!!!)
(may be in lower case)
Pure Ownage is two words that form into one, Pwnage.
The P from Pure is taken and it replace the O from Ownage as it creates a better word than Ownage, Pwnage.
The short saying of Pwnage is Pwn, same as Ownage and Own
PC player 1: I am ownage!
PC player 2: well i am pwnage
PC player 1: pwnage?
PC player 2: yeah a word that own you more