Kill/Death Ratio. Normally used in reference to first person shooter games. Many serious gamers are very concerned on a day to day basis about their current KDR standing on the server they play on. Skill among the first person gaming community is often judged heavily by the KDR of the individual gamer in question. A player with a low KDR is almost gauranteed to be harassed and called a n00b. Low KDR players are often subject to embarassing kills which will be followed by another player saying "You got pwned!"
People should not be judged by religion, race, or wealth but by their KDR.
I had a 5.0 KDR pwning up all the n00bs on the server today.