acciaccatura

from WordNet (r) 3.0 (2006)

acciaccatura
    n 1: an embellishing note usually written in smaller size [syn:
         {grace note}, {appoggiatura}, {acciaccatura}]

from The Collaborative International Dictionary of English v.0.48

Acciaccatura \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.
   [1913 Webster]