bus

bus plural buses also busses especially American English [countable]

1 a large vehicle that people pay to travel onCOLLOCATIONS 
get on a busget off a buswait for a buscatch a bustake a busride a bus American Englishmiss a bus (=be too late to get on a bus)bus fare (=money you pay for a bus journey)bus pass (=a card you buy that allows you to make several bus journeys)bus ride/trip/journeybus route (=the way a bus goes)school bus

There were a lot of people on the bus.

She got on the bus at Clark Street.

 I'll tell you when to get off the bus.

 a line of people waiting for a bus

 Sally had to run to catch the bus.

 I took the bus to the university.

Try riding the bus for a peso or two.

 Hurry up or we'll miss the bus!

by bus

The best way to get there is by bus.

 Unable to afford bus fares, she walked to interviews.

I lost my glasses on the school bus.

2 a circuit that connects the main parts of a computer so that signals can be sent from one part of the computer to another

Definition from the Longman Dictionary of Contemporary English
Advanced Learner's Dictionary.