merger vs unification

merger and unification both are nouns.

Word	Noun	Adjective	Verb	Adverb
merger	Yes	No	No	No
unification	Yes	No	No	No

As nouns, merger and unification are synonyms defined as:

merger and unification: an occurrence that involves the production of a union

Other synonyms of merger include fusion.

merger (noun)	unification (noun)
the combination of two or more commercial companies	the act of making or becoming a single unit
an occurrence that involves the production of a union	an occurrence that involves the production of a union
	the state of being joined or united or linked