coalescence vs unification

coalescence and unification both are nouns.

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

As nouns, unification is a hypernym of coalescence; that is, unification is a word with a broader meaning than coalescence:

coalescence: the union of diverse things into one body or form or group; the growing together of parts
unification: the act of making or becoming a single unit

Other hypernyms of coalescence include conjugation, jointure, union, uniting.

coalescence (noun)	unification (noun)
the union of diverse things into one body or form or group; the growing together of parts	the act of making or becoming a single unit
	an occurrence that involves the production of a union
	the state of being joined or united or linked