waterway vs tailrace

waterway and tailrace both are nouns.

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

As nouns, tailrace is a hyponym of waterway; that is, tailrace is a word with a more specific, narrower meaning than waterway:

waterway: a conduit through which water flows
tailrace: a watercourse that carries water away from a mill or water wheel or turbine

Other hyponyms of waterway include canal, flume, headrace.

waterway (noun)	tailrace (noun)
a conduit through which water flows	a watercourse that carries water away from a mill or water wheel or turbine
a navigable body of water