noun (plural buses; US also busses)
verb (busses, bussing, bussed or buses, busing, bused)
early 19th century: shortening of omnibus
Add -es to make the plurals of nouns that end in -s: (buses).
The different forms of the verb can be spelled with either a single or a double s: (buses, busing, bused or busses, bussing, bussed).