Dreggy, impure, or foreign matter, mixed with any substance, and detracting from its purity; e.g. the dregs or lees of oil or wine, the chaff of…

An instance of this; concrete anything that defiles.

The action of fouling something; the result of this; foul matter, spec. excrement. Also (and earliest) in figurative context.

= feculence, n. 2; literal and figurative. In plural. Impurities.

concrete. Feculent matter; dregs, lees, dross, scum. Also (now chiefly) in stronger sense, filth. literal and figurative.

concrete. That in which contamination is embodied; an impurity.

A polluting agent; esp. a noxious or poisonous substance which pollutes the environment.

That which contaminates.

A substance considered unpleasant or disgusting, esp. because of its dirtiness; dirt, muck, or excrement; (also) a coating or encrustation of this.