unfreeze vs melt

unfreeze is not a noun while melt is a noun.

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

As verbs, unfreeze and melt are synonyms defined as:

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

unfreeze (noun)	melt (noun)
	the process whereby heat changes something from a solid to a liquid

unfreeze (verb)	melt (verb)
become or cause to become soft or liquid	become or cause to become soft or liquid
make (assets) available	reduce or cause to be reduced from a solid to a liquid state, usually by heating
	lose its distinct outline or shape; blend gradually
	become more relaxed, easygoing, or genial
	become less clearly visible or distinguishable; disappear gradually or seemingly
	become less intense and fade away gradually