(1):

(n.) A mixture for fertilizing land; esp., a composition of various substances (as muck, mold, lime, and stable manure) thoroughly mingled and decomposed, as in a compost heap.

(2):

(v. t.) To manure with compost.

(3):

(v. t.) To mingle, as different fertilizing substances, in a mass where they will decompose and form into a compost.

(4):

(n.) A mixture; a compound.