something that serves as a preceding event or introduces what follows; "training is a necessary preliminary to employment"; "drinks were the overture to dinner"
a minor match preceding the main event
designed to orient or acquaint with a situation before proceeding; "a preliminary investigation"
a telecommunication system that transmits images of objects (stationary or moving) between distant points
broadcasting visual images of stationary or moving objects; "she is a star of screen and video"; "Television is a medium because it is neither rare nor well done" - Ernie Kovacs
an electric railway operating below the surface of the ground (usually in a city); "in Paris the subway system is called the `metro' and in London it is called the `tube' or the `underground'"