Definition of "trunk line" []

A direct line between two telephone switchboards. (noun)
The main line of a communications or transportation system. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Use "trunk line" in a sentence

"My headlights picked out the rusted Southern Pacific trunk line where it branched off to the west."

Words like "trunk line"

line

phone line

rail line railway line

subscriber line telephone circuit

telephone line