expire vs stifle

expire is not a noun while stifle is a noun.

Word	Noun	Adjective	Verb	Adverb
expire	No	No	Yes	No
stifle	Yes	No	Yes	No

As verbs, stifle is a hyponym of expire; that is, stifle is a word with a more specific, narrower meaning than expire:

expire: pass from physical life and lose all bodily attributes and functions necessary to sustain life
stifle: be asphyxiated; die from lack of oxygen

Other hyponyms of expire include abort, asphyxiate, suffocate, buy it, pip out, drown, predecease, famish, starve, fall, succumb, yield.

expire (noun)	stifle (noun)
	joint between the femur and tibia in a quadruped; corresponds to the human knee

expire (verb)	stifle (verb)
expel air	suppress or constrain so as to lessen in intensity
pass from physical life and lose all bodily attributes and functions necessary to sustain life	be asphyxiated; die from lack of oxygen
lose validity	suppress in order to conceal or hide
	impair the respiration of or obstruct the air passage of