- (countable) A hub is the middle part of a wheel.
- (countable) A hub is a place where a large amount of traffic meets or passes through.
- London's Heathrow Airport is a big air traffic hub in Europe.
- (countable) (technology) A hub is a simple networking device that sends all of the data (packets) that it gets to all of the other devices that are connected to it.
- Mark bought a cheap hub to connect his home computers together.