Definition and background:
A stringed instrument that is classified as a chordophone that can be either strummed or plucked. A folk instrument of African origin from the guitar family. It has a fretted fingerboard, elongated neck, a circular body, and four or five strings. The body has a soundboard animal skin or parchment like a drum. A fretted instrument which usually has five strings and is plucked with the fingers or a plectrum. used in country music and early jazz.
For more information on the music term "Banjo" check out these other resources:
Wikipedia - Glossary of Musical Terminology
Virginia Tech Multimedia Music Dictionary
ORB -- Medieval Music Glossary