1.NounA stringed musical instrument, of European origin, usually with a fretted fingerboard and six strings, played with the fingers or a plectrum (guitar pick).
"Learning to strum the guitar rhythmically is essential.; She was carrying her guitar in a fancily-decorated case.; The band is looking for a new guitar player."
2.NounAny type of musical instrument of the lute family, characterized by a flat back, along with a neck whose upper surface is in the same plane as the soundboard, with strings along the neck and parallel to the soundboard.