Scum

·vt To sweep or range over the surface of.

II. Scum ·v refuse; recrement; anything vile or worthless.

III. Scum ·vi To form a scum; to become covered with scum. Also used figuratively.

IV. Scum ·vt To take the scum from; to clear off the impure matter from the surface of; to Skim.

V. Scum ·v The extraneous matter or impurities which rise to the surface of liquids in boiling or fermentation, or which form on the surface by other means; also, the scoria of metals in a molten state; dross.