The crossword solution for the term SUFFIX WITH 'VIOLIN' OR 'GUITAR' is IST, which is a three-letter word. IST is an abbreviation of the word 'ISTHMUS', which is a narrow strip of land connecting two larger landmasses. In music, an ISTHMUS is a type of musical bridge that connects two sections of a song, often with a different melody or rhythm. This type of bridge is commonly used in folk and classical music, particularly with string instruments such as the violin and guitar.