life preserver vs preserver

life preserver and preserver both are nouns.

Word	Noun	Adjective	Verb	Adverb
life preserver	Yes	No	No	No
preserver	Yes	No	No	No

As nouns, life preserver and preserver are synonyms defined as:

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

Other synonyms of life preserver include flotation device.

life preserver (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