fuse vs merge

fuse is a noun but merge is not a noun.

Word	Noun	Adjective	Verb	Adverb
fuse	Yes	No	Yes	No
merge	No	No	Yes	No

As verbs, fuse and merge are synonyms defined as:

Other synonyms of fuse include blend, coalesce, combine, commingle, conflate, flux, immix, meld, mix.

fuse (noun)	merge (noun)
any igniter that is used to initiate the burning of a propellant
an electrical device that can interrupt the flow of electrical current when it is overloaded

fuse (verb)	merge (verb)
mix together different elements	become one
make liquid or plastic by heating	mix together different elements
become plastic or fluid or liquefied from heat	join or combine
equip with a fuse; provide with a fuse