Synonyms for Muck (same or very similar meaning)
WordNet sense 1 (any thick messy substance):
goo, gunk, ooze, slime, sludge, guckWordNet sense 2 (fecal matter of animals):
droppings, dungWordNet sense 3 (spread manure, as for fertilization):
manureWordNet sense 4 (soil with mud, muck, or mire):
mire, mud, muck upFrom the ODE community, based on WordNetadd/edit