neutral wire

US /ˈnuːtrəl waɪər/
UK /ˈnuːtrəl waɪər/
"neutral wire" picture
1.

a wire in an electrical circuit that completes the circuit and carries current back to the source, typically maintained at or near ground potential

:
Always connect the neutral wire to the designated terminal.
The electrician checked the voltage between the live and neutral wire.