Coal-black adjective – Of the blackest black; similar to the color of jet or coal. Murky and coal-black are semantically related. In some cases you can use "Murky" instead an adjective phrase "Coal-black".
Murky adjective – Being without light or without much light. Coal-black and murky are semantically related. Sometimes you can use "Coal-black" instead an adjective "Murky". Nearby Words: murk, murkily