What does appoggiatura mean?
The definition of appoggiatura
Ap*pog`gia*tu”ra, n.
Etym: [It., fr. appogiarre to lean, to rest; ap- (L. ad) + poggiare to mount, ascend, poggio hill, fr. L. podium an elevated place.] (Mus.)

A passing tone preceding an essential tone, and borrowing the time it occupies from that; a short auxiliary or grace note one degree above or below the principal note unless it be of the same harmony; — generally indicated by a note of smaller size, as in the illustration above. It forms no essential part of the harmony.