Webster's Revised Unabridged Dictionary · 1913

Compost

Compost (?; 277) , noun

[Old French compost, from Latin compositus, p. p. See Composite.]

1.
A mixture; a compound. [Rare]
A sad compost of more bitter than sweet. — Hammond
2.
(Agriculture) 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.
And do not spread the compost on the weeds To make them ranker. — Shakespeare

Compost , transitive verb

1.
To manure with compost.
2.
To mingle, as different fertilizing substances, in a mass where they will decompose and form into a compost.