Diesis
Diesis , noun
[New Latin, from Greek {not transcribed}, from {not transcribed} to let go through, dissolve; dia` through + {not transcribed} to let go, send.]
1.
(Music) A small interval, less than any in actual practice, but used in the mathematical calculation of intervals.
2.
(Printing) The mark ‡; -- called also double dagger. It is used in printing to indicate a cross reference or footnote