law vs challenge

law and challenge both are nouns.

Word	Noun	Adjective	Verb	Adverb
law	Yes	No	No	No
challenge	Yes	No	Yes	No

law (noun)	challenge (noun)
the learned profession that is mastered by graduate study in a law school and that is responsible for the judicial system	a call to engage in a contest or fight
a rule or body of rules of conduct inherent in human nature and essential to or binding upon human society	questioning a statement and demanding an explanation
a generalization that describes recurring facts or events in nature	a formal objection to the selection of a particular person as a juror
the branch of philosophy concerned with the law and the principles that lead courts to make the decisions they do	a demand by a sentry for a password or identification
legal document setting forth rules governing a particular kind of activity	a demanding or stimulating situation
the collection of rules imposed by authority
the force of policemen and officers

law (verb)	challenge (verb)
	issue a challenge to
	take exception to
	raise a formal objection in a court of law
	ask for identification