water snake vs colubrid

water snake and colubrid both are nouns.

Word	Noun	Adjective	Verb	Adverb
water snake	Yes	No	No	No
colubrid	Yes	No	No	No

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

water snake: any of various mostly harmless snakes that live in or near water
colubrid: mostly harmless temperate-to-tropical terrestrial or arboreal or aquatic snakes

Other hypernyms of water snake include colubrid snake.

water snake (noun)	colubrid (noun)
any of various mostly harmless snakes that live in or near water	mostly harmless temperate-to-tropical terrestrial or arboreal or aquatic snakes