How do you spell Compost

Available Definitions:
1)  n. - A mixture; a compound.
2)  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.
3)  v. t. - To manure with compost.
4)  v. t. - To mingle, as different fertilizing substances, in a mass where they will decompose and form into a compost.