BNC The type of connector that is often used for Coaxial Cables, such as those for Thin-Wire Ethernet or RGB video. Some say that BNC stands for Bayonet Nut Connector (the push and turn action like that used for a Nikon camera lens is often referred to as a bayonet mount, probably because rifle bayonets are mounted that way). Some say that it stands for Bayonet Neil Consulman, for the people (person) who developed the connector (Mr. Bayonet taking the lead, no doubt).