pop off vs stifle

pop off is not a noun while stifle is a noun.

Word	Noun	Adjective	Verb	Adverb
pop off	No	No	Yes	No
stifle	Yes	No	Yes	No

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

pop off: 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 pop off include abort, asphyxiate, suffocate, buy it, pip out, drown, predecease, famish, starve, fall, succumb, yield.

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

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