watercourse vs waterway

watercourse and waterway both are nouns.

Word	Noun	Adjective	Verb	Adverb
watercourse	Yes	No	No	No
waterway	Yes	No	No	No

As nouns, watercourse and waterway are synonyms defined as:

watercourse (noun)	waterway (noun)
a conduit through which water flows	a conduit through which water flows
a natural body of running water flowing on or under the earth	a navigable body of water
natural or artificial channel through which water flows