||Ac*ciac`ca*tu"ra (&?;), n. [It., from acciaccare to crush.] (Mus.) A short grace note, one semitone below the note to which it is prefixed; -- used especially in organ music. Now used as equivalent to the short appoggiatura.

• (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.