汚濁[odaku] pollution
溷濁[kondaku] turbidity
清濁[seidaku] good and evil
濁す[nigosu] to make muddy (a liquid)
濁り[nigori] muddiness

濁り点[nigoriten] voiced consonant marks
濁る[nigoru] to become muddy
濁音[dakuon] sonant
濁点[dakuten] voiced consonant marks (nigori)
濁流[dakuryuu] muddy stream