A Dictionary of Music and Musicians/Acciaccatura
ACCIACCATURA. (Ital. from acciacare, to crush, to pound; Ger. Zusammenschlag; Fr. Pincé etouffé.) A now nearly obsolete description of ornament, available only on keyed instruments, in which an essential note of a melody is struck at the same moment with the note immediately below it, the latter being instantly released, and the principal note sustained alone (Ex. 1). It is generally indicated by a small note with an oblique stroke across the stem (Ex. 2), or when used in chords by a line across the chord itself (Ex. 3).
Its use is now confined exclusively to the organ, where it is of great service in giving the effect of an accent, or sforzando, to either single notes or chords.The term Acciacatura is now very generally applied to another closely allied form of ornament, the short appoggiatura (see that word).
[ F. T. ]