float vs preserver

float and preserver both are nouns.

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

As nouns, preserver is a hyponym of float; that is, preserver is a word with a more specific, narrower meaning than float:

float: something that floats on the surface of water
preserver: rescue equipment consisting of a buoyant belt or jacket to keep a person from drowning

Other hyponyms of float include bob, bobber, bobfloat, cork, chip, flotation device, life preserver, pontoon, raft.

float (noun)	preserver (noun)
an air-filled sac near the spinal column in many fishes that helps maintain buoyancy	rescue equipment consisting of a buoyant belt or jacket to keep a person from drowning
something that floats on the surface of water	a skilled worker who is employed to restore or refinish buildings or antique furniture
a hand tool with a flat face used for smoothing and finishing the surface of plaster or cement or stucco	someone who keeps safe from harm or danger
an elaborate display mounted on a platform carried by a truck (or pulled by a truck) in a procession or parade	a cook who preserves fruits or meat
a drink with ice cream floating in it
the number of shares outstanding and available for trading by the public
the time interval between the deposit of a check in a bank and its payment

float (verb)	preserver (verb)
convert from a fixed point notation to a floating point notation
allow (currencies) to fluctuate
make the surface of level or smooth
put into the water
be in motion due to some air or water current
be afloat either on or below a liquid surface and not sink to the bottom
set afloat
move lightly, as if suspended
circulate or discuss tentatively; test the waters with