noun
mainline
The principal route or connection in a transport or supply network.
The local tracks join the mainline just outside the city.
Etymology
Mainline combines main, meaning principal, with line as a route or connection. It distinguishes the central route from the branches that feed into it.
More examples
- Crews shut down the mainline to repair a leaking valve.
- A smaller pipe connects our building to the water mainline.
- Freight trains share the mainline with passenger trains.
Forms
mainline · mainlines