diesis

noun, plural di·e·ses [dahy-uh-seez] /ˈdaɪ əˌsiz/. Printing.

1. double dagger.

noun plural -ses (-ˌsiːz)

1. printing another name for double dagger
2. music
   1. (in ancient Greek theory) any interval smaller than a whole tone, esp a semitone in the Pythagorean scale
   2. (in modern theory) the discrepancy of pitch in just intonation between an octave and either a succession of four ascending minor thirds (great diesis), or a succession of three ascending major thirds (minor diesis)