The term 'Violin Relative' is a crossword solution that can be filled in with the word 'CELLO', which has five letters. The CELLO is a stringed instrument that is related to the violin, as it is part of the same family of instruments known as the violins. It is larger than the violin and is held between the player's knees when played. It has four strings and is tuned in perfect fifths, similar to the violin. The CELLO is used in many genres of music, including classical, jazz, and folk.