1. Drainage of filth; filth collected from the street or highway; sewage. The streets were exceedingly large, well paved, having many vaults and conveyances under them for sullage. (Evelyn)
2. That which sullies or defiles. It is the privilege of the celestial luminaries to receive no tincture, sullage, or difilement from the most noisome sinks and dunghills here below. (south)
3. The scoria on the surface of molten metal in the ladle.
4. (Science: physics) silt; mud deposited by water. Sullage piece, the sprue of a casting. See Sprue, 1 .