go-between; intermediary; mediator
Refers to a person who acts as a communication channel between two parties, often in business or diplomacy. The metaphor is of a pipe connecting two sides.
He acted as a go-between for the two companies and brought the negotiations to a conclusion.
At international conferences, interpreters often serve as intermediaries.
Compound of パイプ (from English 'pipe', metaphorically a conduit) and 役 (role). The term likens a person's function to a pipe that connects two parties.