Source : Webster's Revised Unabridged Dictionary (1913)

Segno \Se"gno\, n. [It. See {Sign}.] (Mus.)
   A sign. See {Al segno}, and {Dal segno}.

Source : WordNet®

segno
     n : (music) a notation written at the beginning or end of a
         passage that is to be repeated
     [also: {segni} (pl)]