This is the 9677th most frequent Russian word.
черная
"Черная" means "black" (feminine form).
Here, 'черное' is used as an adjective modifying the noun 'платье' in the accusative case to agree with the direct object in a sentence.
Она надела черное платье.
She wore a black dress.
In this sentence, 'черной' is an adjective describing the noun 'ночь,' agreeing with it in form and gender in the instrumental case used in the construction.
Ночь была черной и беззвездной.
The night was black and starless.
Here, 'Черный' is an adjective modifying the noun 'кофе,' agreeing with it in the nominative case to depict a particular characteristic trait of the subject.