rap (v.2)youdaoicibaDictYouDict
"talk informally, chat," 1929, popularized c. 1965 in Black English, possibly first in Caribbean English and from British slang meaning "say, utter" (1879), originally "to utter a sudden oath" (1540s), ultimately from rap (n.). As a noun in this sense from 1898. Meaning "to perform rap music" is recorded by 1979. Related: Rapped; rapping.
rapping (n.)youdaoicibaDictYouDict
c. 1400, verbal noun from rap (v.1). Meaning "talking" is from 1969; meaning "rap music performance" is from 1979, from rap (v.2).