television vs TV

television and TV both are nouns.

Word	Noun	Adjective	Verb	Adverb
television	Yes	No	No	No
TV	Yes	No	No	No

As nouns, television and TV are synonyms defined as:

television and TV: broadcasting visual images of stationary or moving objects

Other synonyms of television include telecasting, video.

television (noun)	TV (noun)
a telecommunication system that transmits images of objects (stationary or moving) between distant points	broadcasting visual images of stationary or moving objects
an electronic device that receives television signals and displays them on a screen
broadcasting visual images of stationary or moving objects