caveat emptor vs precept

caveat emptor and precept both are nouns.

Word	Noun	Adjective	Verb	Adverb
caveat emptor	Yes	No	No	No
precept	Yes	No	No	No

As nouns, precept is a hypernym of caveat emptor; that is, precept is a word with a broader meaning than caveat emptor:

caveat emptor: a commercial principle that without a warranty the buyer takes upon himself the risk of quality
precept: rule of personal conduct

Other hypernyms of caveat emptor include principle.

caveat emptor (noun)	precept (noun)
a commercial principle that without a warranty the buyer takes upon himself the risk of quality	a doctrine that is taught
	rule of personal conduct