tidewater river vs tidal stream

tidewater river and tidal stream both are nouns.

Word	Noun	Adjective	Verb	Adverb
tidewater river	Yes	No	No	No
tidal stream	Yes	No	No	No

As nouns, tidewater river and tidal stream are synonyms defined as:

tidewater river and tidal stream: a stream in which the effects of the tide extend far upstream

Other synonyms of tidewater river include tidal river, tidewater stream.

tidewater river (noun)	tidal stream (noun)
a stream in which the effects of the tide extend far upstream	a stream in which the effects of the tide extend far upstream