die off vs die

die off is not a noun while die is a noun.

Word	Noun	Adjective	Verb	Adverb
die off	No	No	Yes	No
die	Yes	No	Yes	No

die off (noun)	die (noun)
	a small cube with 1 to 6 spots on the six faces; used in gambling to generate random numbers
	a device used for shaping metal
	a cutting tool that is fitted into a diestock and used for cutting male (external) screw threads on screws or bolts or pipes or rods

die off (verb)	die (verb)
become extinct	pass from physical life and lose all bodily attributes and functions necessary to sustain life
	disappear or come to an end
	suffer spiritual death; be damned (in the religious sense)
	stop operating or functioning
	lose sparkle or bouquet
	to be on base at the end of an inning, of a player
	cut or shape with a die
	be brought to or as if to the point of death by an intense emotion such as embarrassment, amusement, or shame
	languish as with love or desire
	feel indifferent towards
	suffer or face the pain of death