muck around

noun

1. moist manure
2. black earth containing decaying matter, used as a fertilizer
3. 1. mire; mud
   2. anything unclean or degrading; dirt; filth

Origin: ME muk < or akin to ON myki, dung < IE base *meuk-, slippery, viscous > meek, L mucus

transitive verb

1. to fertilize with muck
2. Informal to dirty with or as with muck: often with up
3. Chiefly Brit., Slang to make a mess of; bungle: often with up
4. Chiefly Brit. to clean (esp. a stable); remove muck from: usually used with out