kanji used phonetically for their on-reading as syllables
A historical linguistic term referring to the use of kanji for their sound (on-reading) to represent syllables, before the development of kana. Compare 訓仮名 (kun-gana) and 万葉仮名 (man'yōgana).
See also: 訓仮名 (くんがな) · 万葉仮名 (まんようがな)
On-gana are characters used to represent Japanese syllables by employing the on-reading of kanji.
A broader term for the early system of using kanji phonetically, encompassing both 音仮名 and 訓仮名.
Compound of 音 (on, 'sound' or 'on-reading') and 仮名 (kana, 'borrowed characters'). The term refers to the phonetic use of kanji based on their Sino-Japanese readings.