closed_circuit has definitions from the fields of physics,electronics
1
[ noun ] (physics,electronics) a complete electrical circuit around which current flows or a signal circulates

Synonyms

loop

Used in print

(Walter H. Buchsbaum, "Advances in Medical Electronics"...)

Commonly used electronic_devices which are found in practically every hospital are closed-circuit TV and audio_systems for internal paging and instruction , along with radiation counters , timers , and similar devices .

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