unfreeze vs thaw

unfreeze is not a noun while thaw is a noun.

Word	Noun	Adjective	Verb	Adverb
unfreeze	No	No	Yes	No
thaw	Yes	No	Yes	No

As verbs, unfreeze and thaw are synonyms defined as:

Other synonyms of unfreeze include dethaw, dissolve, melt, unthaw.

unfreeze (noun)	thaw (noun)
	a relaxation or slackening of tensions or reserve; becoming less hostile
	warm weather following a freeze; snow and ice melt
	the process whereby heat changes something from a solid to a liquid

unfreeze (verb)	thaw (verb)
become or cause to become soft or liquid	become or cause to become soft or liquid
make (assets) available