Diesis (scale theory)

The diesis (precisely the mosdiesis) of a mos scale is the interval that is the difference between two enharmonic notes, i.e. the diminished mossecond (a minor mossecond diminished by a moschroma). In particular, the diesis or enharmonic diesis in the diatonic scale is the diminished second, for example, the interval of C#-Db.