ὑποδιαστολή

Etymology
From.

Noun

 * 1)  The hypodiastole, a mark used in scripta continua Classical and Byzantine Greek to note that a series of letters should be read as two words rather than all together, now identical to the comma.

Usage notes
The separately encoded hypodiastole in Unicode is only intended for historical documents from late Antiquity and the early Byzantine era. The few remaining instances of hypodiastoles after the development of spacing in late Byzantine Greek—such as ό,τι—formally use the comma instead and informally see the mark omitted.