Definition from Wiktionary, the free dictionary
- (music) A short grace note (theoretically taking no time at all), occurring on the beat occupied by the main note to which it is prefixed, one scale-step higher or lower than that main note. (Sometimes equivalent, therefore, to a short appoggiatura, but in Baroque music interpreted differently and more strictly.) Written as a note lighter in appearance, typically a quaver (eighth note), with an oblique stroke through the stem.
short grace note occurring on the beat occupied by the main note
acciaccatura f (plural acciaccaturas)