The term 'Mandolin Cousins' refers to two stringed instruments, the mandolin and the lute. The lute is a five-letter word that is related to the mandolin. Both instruments have a long history and are still popular today. The mandolin is a small, plucked string instrument of the lute family, while the lute is a larger, fretted instrument with a deep, round back. Both instruments are used in a variety of musical genres, from classical to folk music.