sound law vs natural law

sound law and natural law both are nouns.

Word	Noun	Adjective	Verb	Adverb
sound law	Yes	No	No	No
natural law	Yes	No	No	No

As nouns, natural law is a hypernym of sound law; that is, natural law is a word with a broader meaning than sound law:

sound law: a law describing sound changes in the history of a language
natural law: a rule or body of rules of conduct inherent in human nature and essential to or binding upon human society

Other hypernyms of sound law include law.

sound law (noun)	natural law (noun)
a law describing sound changes in the history of a language	a rule or body of rules of conduct inherent in human nature and essential to or binding upon human society