off the hook vs safe

off the hook is not a noun while safe is a noun.

Word	Noun	Adjective	Verb	Adverb
off the hook	No	Yes	No	No
safe	Yes	Yes	No	No

off the hook (noun)	safe (noun)
	strongbox where valuables can be safely kept
	contraceptive device consisting of a sheath of thin rubber or latex that is worn over the penis during intercourse
	a ventilated or refrigerated cupboard for securing provisions from pests

off the hook (adjective)	safe (adjective)
freed from danger or blame or obligation	free from danger or the risk of harm
	having reached a base without being put out
	financially safe
	(of an undertaking) secure from risk