creek vs watercourse

creek and watercourse both are nouns.

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

As nouns, watercourse is a hypernym of creek; that is, watercourse is a word with a broader meaning than creek:

creek: a natural stream of water smaller than a river (and often a tributary of a river)
watercourse: a natural body of running water flowing on or under the earth

Other hypernyms of creek include stream.

creek (noun)	watercourse (noun)
a natural stream of water smaller than a river (and often a tributary of a river)	a conduit through which water flows
	a natural body of running water flowing on or under the earth
	natural or artificial channel through which water flows