compost
/ˈkɑːmˌpoʊst/ /Brit ˈk{scriptainv}mˌp{scriptainv}st/
noun
[noncount] :a decayed mixture of plants (such as leaves and grass) that is used to improve the soil in a garden
verb
-posts; -posted; -posting
[+ obj] :to change (plant materials) into compost