coal-black

CIDE DICTIONARY

coal-black, a. 

 As black as coal; jet black; very black.  Dryden.  [1913 Webster]

ROGET THESAURUS

coal-black

Blackness

VB be black, render black, blacken, infuscate, denigrate, blot, blotch, smutch, smirch, darken, black, sable, swarthy, somber, dark, inky, ebony, ebon, atramentous, jetty, coal-black, jet-black, fuliginous, pitchy, sooty, swart, dusky, dingy, murky, Ethiopic, low-toned, low in tone, of the deepest dye, black as jet, black as my hat, black as a shoe, black as a tinker's pot, black as November, black as thunder, black as midnight, nocturnal, nigrescent, gray, obscure.