coaxial cable (coax)
1. A cable consisting of a center conductor surrounded by an insulating material and a concentric outer conductor and optional protective covering, all of circular cross-section. Synonym (when combined with others under a common sheath) coaxial tube.
2. A cable consisting of multiple coaxial tubes under a single protective sheath.
Note: Coaxial cables are used primarily for CATV and other wideband, video, or rf applications.