- a manually or automatically operated telephone facility that handles communications within an office, office building, or organization and that is connected to the public telephone network.
Origin of PBX
P(rivate) B(ranch) Ex(change)
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for pbx
It is a PBX machine and is in the nature of a board up on the wall and it has several sections.Warren Commission (10 of 26): Hearings Vol. X (of 15)
The President's Commission on the Assassination of President Kennedy
- private branch exchange; a telephone system that handles the internal and external calls of a building, firm, etc