debase vs water down

debase and water down both are verbs.

Word	Noun	Adjective	Verb	Adverb
debase	No	No	Yes	No
water down	No	No	Yes	No

As verbs, water down is a hyponym of debase; that is, water down is a word with a more specific, narrower meaning than debase:

debase: corrupt, debase, or make impure by adding a foreign or inferior substance; often by replacing valuable ingredients with inferior ones
water down: thin by adding water to

Other hyponyms of debase include doctor, doctor up, sophisticate.

debase (verb)	water down (verb)
lower in value by increasing the base-metal content	make less strong or intense
corrupt, debase, or make impure by adding a foreign or inferior substance; often by replacing valuable ingredients with inferior ones	thin by adding water to
corrupt morally or by intemperance or sensuality