BNC

A type of connector that uses a twist and lock type of retention. No one knows what BNC stands for, but there are several theories, including British Naval Connector, Bayonet Nut Connector, and Bayonet Neill Concelman (named for the alleged creators of the connector). Of the three, the latter seems to be the most feasible.

BNC connectors terminate to coaxial cable and are commonly used with video and radio communication equipment, and also older Ethernet networks.