Bus/bʌs/ Definition 1 of 4Pro Tip 1/3Public Transit The term bus is often associated with public transport systems. She caught the bus to visit her grandmother. Pro Tip 2/3Plural Form When talking about more than one, use 'buses' as the plural form. There are three buses that stop here. Pro Tip 3/3On or Off Use 'on' when boarding and 'off' when getting down. He got on the bus at Chelsea Street and off at Main Square.