To make (something) brown; to brown.
To make (something) dark or dusky (“having a rather dark shade of colour”); to brown, to darken.
To become or make dark or dusky; to brown, to darken.
To become or make brown; to brown.
To manure with muck.
To shovel muck.
To vomit.
To do a dirty job.
To pass, to fold without showing one's cards, often done when a better hand has already been revealed.
Heroin.
Semen.
Soft (or slimy) manure.
The pile of discarded cards.
Anything filthy or vile. Dirt; something that makes another thing dirty.
Grub, slop, swill
Slimy mud, sludge.