Tuner (noun)

A device or tool used to adjust the pitch of a musical instrument or a radio or television receiver.

Origin:

From the verb "to tune" meaning "to adjust the pitch of a musical instrument or a radio or television receiver".

Examples:

1. The guitar player used a tuner to tune his instrument before the performance.
2. The piano tuner was adjusting the pitch of the piano.
3. The tuner on the television was used to find the right channel.
4. The radio tuner allowed the listener to scan through the different stations.
5. The tuning fork is a simple type of tuner used by musicians.