A conglomerate is a group of things, especially companies, put together to form one. If you are rich enough to buy a TV network, a record company, several newspapers, and a radio station, you too can own a media conglomerate.
The root of conglomerate is glomus, a Latin word for “ball.” So think of a conglomerate as a bunch of different things balled together. Before it came to describe giant corporations, a conglomerate was a rock formed from different kinds of minerals. Conglomerate can also be used as a verb — like when your media companies conglomerated successfully.