closed-circuit television

Từ điển WordNet v3.1 - WordNet Dictionary

noun

a television system that is not used for broadcasting but is connected by cables to designated monitors (as in a factory or theater)
• Topics:
factory, mill, manufacturing plant, manufactory, dramaturgy,
dramatic art, dramatics, theater, theatre
• Hypernyms:
television, television system
• Hyponyms:
surveillance system