Nouns

(n)sludge, slime, goo, goop, gook, guck, gunk, muck, oozeany thick, viscous matter
(n)droppings, dung, muckfecal matter of animals

Verbs

(v)muckremove muck, clear away muck, as in a mine
(v)manure, muckspread manure, as for fertilization
(v)mire, muck, mud, muck upsoil with mud, muck, or mire“The child mucked up his shirt while playing ball in the garden”