the.com/dirty
A condition of soil and conscience, equally hard to wash out.
means Covered in dirt, or morally tainted, unfair, or sexually crude depending on context.
from From Old Norse drit, meaning excrement; Middle English dritty literally meant covered in dung before politely abstracting into general filth.
Sound swapOriginal dritty flipped letters to become dirty.
Money slangDirty money means cash earned through crime.
Card gamesDirty pool means cheating, not literal grime.