tv vs receiving system

tv and receiving system both are nouns.

Word	Noun	Adjective	Verb	Adverb
tv	Yes	No	No	No
receiving system	Yes	No	No	No

As nouns, receiving system is a hypernym of tv; that is, receiving system is a word with a broader meaning than tv:

tv: an electronic device that receives television signals and displays them on a screen
receiving system: set that receives radio or tv signals

Other hypernyms of tv include receiver.

tv (noun)	receiving system (noun)
an electronic device that receives television signals and displays them on a screen	set that receives radio or tv signals