extinguisher vs asphyxiator

extinguisher and asphyxiator both are nouns.

Word	Noun	Adjective	Verb	Adverb
extinguisher	Yes	No	No	No
asphyxiator	Yes	No	No	No

As nouns, extinguisher and asphyxiator are synonyms defined as:

extinguisher and asphyxiator: a manually operated device for extinguishing small fires

Other synonyms of extinguisher include fire extinguisher.

extinguisher (noun)	asphyxiator (noun)
a manually operated device for extinguishing small fires	a manually operated device for extinguishing small fires