"African-American vernacular English," 1975, as title of a book edited by U.S. professor Robert L. Williams (1930-2020), who is said to have coined the word as a blend of ebony and phonics.
Entries linking to ebonics
ebony n.
dark, hard wood favored for carving, musical instruments, etc., 1590s, perhaps an extended form of Middle English ebon, or from hebenyf (late 14c.), perhaps a Middle English misreading of Latin hebeninus "of ebony," from Greek ebeninos, from ebenos "ebony," probably from Egyptian hbnj or another Semitic source. Figurative use to suggest intense blackness is from 1620s. As an adjective, "of ebony, made of ebony," from 1590s; in reference to skin color of Africans, by 1813. French ébène, Old High German ebenus (German Ebenholz) are from Latin ebenus.
phonics n.
1680s, "phonetics, the doctrine or science of sound," especially of the human voice, from Greek phōnē "sound, voice" (from PIE root *bha- (2) "to speak, tell, say") + -ics.
As the name of a method of teaching reading by associating letters or groups of letters with particular sounds in an alphabetic writing system, especially as correlations between sound and symbol, it is attested by 1901 and became prominent in that sense after 1950, though the systematic method itself dates from the 1830s.