Source : Webster's Revised Unabridged Dictionary (1913)

Solfeggio \Sol*feg"gio\, n.[It., fr. solfa the gamut.] (Mus.)
   The system of arranging the scale by the names do, re, mi,
   fa, sol, la, si, by which singing is taught; a singing
   exercise upon these syllables.

Source : WordNet®

solfeggio
     n 1: singing using solfa syllables to denote the notes of the
          scale of C major [syn: {solmization}, {solfege}]
     2: a voice exercise; singing scales or runs to the same
        syllable [syn: {solfege}]
     [also: {solfeggi} (pl)]