free vs spare

free and spare both are nouns.

Word	Noun	Adjective	Verb	Adverb
free	Yes	Yes	Yes	Yes
spare	Yes	Yes	Yes	No

As adjectives, free and spare are synonyms defined as:

As verbs, spare is a hyponym of free; that is, spare is a word with a more specific, narrower meaning than free:

Other hyponyms of free include derestrict, deregulate, dispense, forgive.

free (noun)	spare (noun)
people who are free	a score in tenpins; knocking down all ten after rolling two balls
	an extra car wheel and tire for a four-wheel vehicle
	an extra component of a machine or other apparatus

free (adjective)	spare (adjective)
not limited or hampered; not under compulsion or restraint	lacking in magnitude or quantity
not held in servitude	thin and fit
unconstrained or not chemically bound in a molecule or not fixed and capable of relatively unrestricted motion	lacking embellishment or ornamentation
not literal	not taken up by scheduled activities
completely wanting or lacking	more than is needed, desired, or required
not fixed in position	kept in reserve especially for emergency use
costing nothing
not taken up by scheduled activities
not occupied or in use

free (verb)	spare (verb)
make (assets) available	use frugally or carefully
let off the hook	give up what is not strictly needed
free or remove obstruction from	refrain from harming
remove or force out from a position	save or relieve from an experience or action
release (gas or energy) as a result of a chemical reaction or physical decomposition
part with a possession or right
relieve from
grant freedom to; free from confinement
make (information) available for publication
free from obligations or duties
grant relief or an exemption from a rule or requirement to

free (adverb)	spare (adverb)
without restraint