Some television has ceased trading with Silverstone, say (6,7)

I believe the answer is:

closed circuit

I'm a little stuck... Click here to teach me more about this clue!

'some television' is the definition.
(closed-circuit television is a kind of television)

I cannot understand how the rest of the clue works.

(Other definitions for closed circuit that I've seen before include "Sort of TV" , "Like security cameras" .)

I've seen this clue in The Daily Express.

Want a hint initially instead of a full solution? Install my app