What does "diesis" mean?

Any of several intervals, smaller than a tone, in ancient Greek music.

What is a synonym for "diesis"?

Common synonyms include: comma, double dagger, double obelisk, microinterval, syntonic comma.

/ˈdaɪ.ə.sɪs/ noun

noun ·Rare ·Advanced level

Noun

1
Any of several intervals, smaller than a tone, in ancient Greek music.
2
a character used in printing to indicate a third cross reference or footnote after the asterisk and the dagger have been used wordnet
3
The double dagger sign (‡).

From Ancient Greek δίεσις (díesis, “sending through, the smallest interval in the scale”).