flotation device vs preserver

flotation device and preserver both are nouns.

Word	Noun	Adjective	Verb	Adverb
flotation device	Yes	No	No	No
preserver	Yes	No	No	No

As nouns, flotation device and preserver are synonyms defined as:

flotation device and preserver: rescue equipment consisting of a buoyant belt or jacket to keep a person from drowning

Other synonyms of flotation device include life preserver.

flotation device (noun)	preserver (noun)
rescue equipment consisting of a buoyant belt or jacket to keep a person from drowning	rescue equipment consisting of a buoyant belt or jacket to keep a person from drowning
	a skilled worker who is employed to restore or refinish buildings or antique furniture
	someone who keeps safe from harm or danger
	a cook who preserves fruits or meat