High Quality Content by WIKIPEDIA articles! The spiritus asper is a diacritical mark used in the polytonic orthography. In ancient Greek, it indicates initial aspiration, or the presence of the voiceless glottal fricative at the beginning of a word. It was maintained in the polytonic orthography even after the /h/ sound disappeared from the Greek language during the Hellenistic period, but has been dropped in the modern monotonic orthography.