1. Plural of omnibus; large buses or motor coaches designed to carry many passengers.
Usage: Common in British English; less frequent in modern American usage
2. Plural of omnibus; collections or volumes containing multiple works or selections by one or more authors.
Usage: Literary or publishing context

Examples

• The city purchased several new omnibusses to expand public transportation.
• During rush hour, the omnibusses were packed with commuters heading downtown.
• The library acquired omnibusses of classic literature for the new reading room.
• Victorian omnibusses were a common sight on London streets in the 19th century.
• The transit authority scheduled omnibusses to run every fifteen minutes on weekdays.