According to Grammarist:
“Notwithstanding Great Caesar’s assertion regarding ‘busses’ as being a kiss (an archaic definition retained only in very few dialects), busses is commonly accepted as the correct form for the verb ‘to bus’ as in he/she/it busses. Buses is the plural of the noun ‘bus’.”
You can hear the singular “buss” in this song, ‘Spin on a Red Brick Floor’: take it away, Nanci Griffith:
Busses,
Glosso
xoxo
Hat tip to Rona