black has 37 distinct synonyms spread across 15 of its 22 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its one recorded opposite is white.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
being of the achromatic color of maximum darkness; having little or no hue owing to absorption of almost all incident light
“black leather jackets”
of or belonging to a racial group especially of sub-Saharan African origin
“a great people--a black people--...injected new meaning and dignity into the veins of civilization”
(of events) having extremely unfortunate or dire consequences; bringing ruin
“the stock market crashed on Black Friday”
distributed or sold illicitly
“the black economy pays no taxes”
(used of conduct or character) deserving or bringing disgrace or shame
“Man...has written one of his blackest records as a destroyer on the oceanic islands”
the quality or state of the achromatic color of least lightness (bearing the least resemblance to white)
British chemist who identified carbon dioxide and who formulated the concepts of specific heat and latent heat (1728-1799)
popular child actress of the 1930's (born in 1928)
a person with African ancestry, "Negro" and "Negroid" are archaic and pejorative today
black clothing (worn as a sign of mourning)
“the widow wore black”
3 of the 22 recorded senses carry no synonym, antonym or related term, so they are not shown above. Every sense, with its definition and examples, is on the full entry for black.
Synonyms, antonyms and the broader and narrower relations for black come from Princeton University’s WordNet. Full sources and licences.