In light of yesterday's news that Dave Mustaine has endorsed Rick Santorum, Slog tipper Eric suggests that we come up with a Santorum-related definition for "Mustaine." I think his definition sounds just about perfect:

mustaine (noun): a fresh, malodorous smear of bodily fluids—usually santorum—on the upper lip, in the manner of a 'milk mustache'.

Thank you, Eric, and also ewwwww.