The crossword solution for the term 'FIXES, AS AN INSTRUMENT' is 'RETUNES', which has 7 letters. Retuning an instrument is a process of adjusting the strings and other components of the instrument to achieve the desired sound. This process can involve tightening or loosening the strings, adjusting the bridge, and making other adjustments to the instrument. It is important to retune an instrument regularly to ensure that it is producing the best possible sound.