Rough breathing

In the polytonic orthography of Ancient Greek, the rough breathing ( or daseîa; dasía; Latin spiritus asper), is a diacritical mark used to indicate the presence of an sound before a vowel, diphthong, or rho. It remained in the polytonic orthography even after the Hellenistic period, when the sound disappeared from the Greek language. In the monotonic orthography of Modern Greek phonology, in use since 1982, it is not used at all.