Semitone
/ˈsemitəʊn/
Definition 1 of 1
Pro Tip 1/3Musical Precision
A semitone refers to the precise pitch change in music, important for harmony and melody. 
She practiced her scales, carefully ascending in semitones.
Pro Tip 2/3Instrument Tuning
On many instruments, adjusting by a semitone changes the pitch slightly but noticeably. 
He tuned his guitar string up by a semitone to match the correct pitch.
Pro Tip 3/3Technical Term
Semitone is a technical term, used when discussing music theory, composition, or performance. 
The composer indicated to increase the note by a semitone.