The term RELATIVE OF A MANDOLIN can be answered by two crossword solutions: SITAR (5 letters) and LUTE (4 letters). The SITAR is a stringed instrument originating from India, and is a relative of the mandolin. It has a long neck with a gourd-shaped body and usually has 7 strings. The LUTE is a plucked string instrument that has been around since the Middle Ages. It has a pear-shaped body and a fretted neck, and usually has 6 or 7 strings. Both the SITAR and the LUTE are relatives of the mandolin, which is a stringed instrument with a fretted neck and a round body.