dièse (from French) or diesis (from Greek δίεσις)[a] – means higher in pitch.
The ♯ symbol derives from a square form of the letter b (see History of notation of accidentals for more information).
A double sharp () is indicated by the symbol and raises a note by two chromatic semitones.
[1] A half sharp, or demisharp () raises a note by approximately a quarter tone.
A sharp-and-a-half, three-quarter-tone sharp, or sesquisharp () raises a note by three quarter tones.
If a sharp is used as an accidental, it can be cancelled on a subsequent similar note in the staff, measure and octave by using a flat (♭) or a natural (♮).