Something that’s murky is dim, gloomy or hard to see through clearly. Think of the dark fog around a haunted house or the cloudy, muddy water in a swamp.
Rarely used before the 17th century, this adjective came about by adding a “y” to the word murk. Murk itself evolved from myrkr, a Norse word for “darkness.” Things that are murky are unclear; that goes for murky, sediment-filled lakes, shady business deals, and arguments that don’t seem to make any sense.
(of liquids) clouded as with sediment
dark or gloomy