tuner

noun6

1. •
   A person who tunes a piano or organ.
2. •
   The component of an audio system that receives radio broadcasts.
3. •
   A device, electronic or mechanical, that helps a person tune a musical instrument by showing the deviation of the played pitch from the desired pitch.
4. •
   On a musical instrument, a peg or mechanical device that changes the tension, and hence pitch, of a string.
5. •
   (informal) A musical.
6. •
   (no longer used) One who sings or makes music.