sportscaster vs sports announcer

sportscaster and sports announcer both are nouns.

Word	Noun	Adjective	Verb	Adverb
sportscaster	Yes	No	No	No
sports announcer	Yes	No	No	No

As nouns, sportscaster and sports announcer are synonyms defined as:

sportscaster and sports announcer: an announcer who reads sports news or describes sporting events

Other synonyms of sportscaster include sports commentator.

sportscaster (noun)	sports announcer (noun)
an announcer who reads sports news or describes sporting events	an announcer who reads sports news or describes sporting events