\Di"e*sis\, n.; pl. {Dieses}. [NL., fr. Gr. ?, fr. ? to
let go through, dissolve; dia` through + ? to let go, send.]
1. (Mus.) A small interval, less than any in actual practice,
   but used in the mathematical calculation of intervals.
2. (Print.) The mark [dag]; -- called also {double dagger}.