backwater vs body of water

backwater and body of water both are nouns.

Word	Noun	Adjective	Verb	Adverb
backwater	Yes	No	No	No
body of water	Yes	No	No	No

As nouns, body of water is a hypernym of backwater; that is, body of water is a word with a broader meaning than backwater:

backwater: a body of water that was created by a flood or tide or by being held or forced back by a dam
body of water: the part of the earth's surface covered with water (such as a river or lake or ocean)

Other hypernyms of backwater include water.

backwater (noun)	body of water (noun)
a place or condition in which no development or progress is occurring	the part of the earth's surface covered with water (such as a river or lake or ocean)
a body of water that was created by a flood or tide or by being held or forced back by a dam