muckiest
muck-i-est
adjective
The superlative form of 'mucky', meaning most covered in dirt or filth.
"That was the muckiest job I've ever had to do."
Thesaurus
Synonyms: marshy, sloppy, muddy, boggy, miry, wet, squashy, sloughy, quaggy, mucky, soggy, waterlogged