lineman's handset - Computer Definition
A portable telephone used by telephone repair people that connects to a telephone line with two alligator clips. Used to make or monitor calls, the clips can pierce the insulation of the wires if necessary; however, the clips are typically attached to bare wires, punch blocks or wiring terminals. Also commonly called a "butt set" for two reasons: the lineman can "butt in" on a conversation, and it often clips to a belt and hangs over the person's rear end. See lineman.