'rapper' originates from English, specifically from the word 'rap' combined with the agentive suffix '-er', where 'rap' originally meant 'a quick strike' and later came to mean 'talk' and then the musical form 'rap'.

'rap' shifted from an earlier sense of 'a blow or strike' (Middle English/early modern uses) to slang meaning 'talk' or 'chat' in African American English in the 20th century; the musical sense 'rap' developed in the mid-20th century, and 'rapper' (one who raps) arose from that musical sense.

Initially 'rap' referred to a physical 'blow' and then to 'talk'; over time it evolved into the musical/performative meaning 'to perform rhythmic spoken lyrics', so 'rapper' came to mean 'a performer of rap music'.