The classic definition is that of a colloquialism to mean short-tempered, snappish, or irritable. It is also a word used by author Lewis Carroll that refers to an imaginary beast. "Snarky" is making it's way onto the Web, primarily used by gamers, to mean a sort of "unknown" type of occurence, or unknown thing, (which in this case, ironically is the word itself). You may hear it in mainstream usage like this, "Who knows what Dick Cheney 's doing, snarking around in his undisclosed location?" or for example, "The GOP hit men such as the Swift Boat Veterans for Truth were snarking John Kerry prior to the election."