1. A thin white or gray film of soap, dirt, and skin cells that accumulates around the tub, tiles, or glass door of a shower. I don't think the previous owners of this place ever cleaned their bathrooms properly. The shower scum alone must have been an inch thick! This spray promises to wash away shower scum without any need to scrub!
2. An extremely repugnant, vile, wretched person. You're worse than a rat, worse than a maggot—you're nothing but shower scum! I would never let my daughter date shower scum like you!