Simple Definition:

Coaxial refers to a type of cable or connector that has a central conductor [a material that allows the flow of electricity] surrounded by a tubular [tube-shaped] insulating layer, which is then enclosed by an outer conductor. The term “coaxial” is also used to describe electronic devices or systems that use this type of cable or connector.

For example, a coaxial cable is commonly used to connect a television to an antenna, satellite dish, or cable box. Another example would be a coaxial connector used to connect a video camera to a monitor.

Very Simple Definition:

Coaxial means a special kind of wire or connector that helps connect different electronic devices. It is often used to connect a TV to an antenna or cable box.