To remove the layer of scum from (a liquid etc.).
To remove (something) as scum.
To startscum or savescum.
To become covered with scum.
Semen.
A layer of impurities that accumulates at the surface of a liquid (especially molten metal or water).
A greenish water vegetation (such as algae), usually found floating on the surface of ponds
A reprehensible person or persons.
The topmost liquid layer of a cesspool or septic tank.
To emit foam; to froth; said of the emission of yeast from beer during fermentation.
Any plant of the genus Euphorbia, a diverse genus of over 2,000 species.