diacritical mark ( ៊ ), which serves to convert the A-series consonants ប bɑɑ, ស sɑɑ, ហ hɑɑ, and អ ʔɑɑ into O-series ប៊ bɔɔ, ស៊ sɔɔ, ហ៊ hɔɔ, and អ៊ ʔɔɔ
Headley
Noun
Diacritical mark ( ៊ (៊)) written above A-series consonants lacking an O-series counterpart (ប, ស, ហ, អ) to convert them to O-series.
Wiktionary