Unit of measure that is the length of wiring between two devices, which has to account for the path taken to avoid obstacles or running in an unsuitable location. For example, a computer and an Ethernet switch may be 3 meters apart, but if they are at opposite sides of the room, the path of the cable will have to go halfway around the room, possibly up and down a doorframe resulting in a cable run of, say 8 meters.

Thus the PC is said to be 8 cable-meters away from the hub.

Not to be confused with a CableMeter™ made by Fluke, diagnostic equipment for checking cabling quality.

Kudos to elem_125 for the idea.