banjo (n.) Look up banjo at Dictionary.com
"guitar-like musical instrument with a circular body covered in front with stretched parchment, like a tambourine," 1764, in various spellings (Thomas Jefferson has banjar), American English, usually described as of African origin, probably akin to Bantu mbanza, name of an instrument resembling a banjo. The word has been influenced by colloquial pronunciation of bandore (1560s in English), a 16c. lute-like stringed instrument, from Portuguese bandurra, from Latin pandura (see mandolin). The origin and the influence might be the reverse of what is here described. Related: Banjoist. The banjo-clock (1891) was so called for its shape.