Skor is a Tauron word, which is a more vulgar term for the word "crap." It can be used as an exclamation or a noun.
In "Rebirth", Sam Adama tells his nephew, Willie, "Nice car. Looks like "skor", but it's got 350 under the hood, a triple-mounted clutch, which most knuckleheads will tell you is a bad thing."