A person who tunes musical instruments, especially pianos. The piano tuner arrived to adjust the strings and ensure the instrument was in perfect pitch.
A device used to adjust the frequency of a radio or television receiver to receive a particular station. He used the tuner to find his favorite radio station on the old stereo system.
A component in a car audio system that allows the user to select and listen to radio stations. The car's tuner was set to the local news station for the morning commute.
A device or software used to adjust the pitch of a musical instrument. She used a digital tuner to ensure her guitar was perfectly in tune before the performance.
A company, specialist, or enthusiast who modifies motor vehicles to improve their performance or appearance. The tuner upgraded the suspension and installed a new exhaust system to make the car track-ready.