coalescency vs coalescence

coalescency and coalescence both are nouns.

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

As nouns, coalescency and coalescence are synonyms defined as:

coalescency and coalescence: the union of diverse things into one body or form or group; the growing together of parts

Other synonyms of coalescency include coalition, concretion, conglutination.

coalescency (noun)	coalescence (noun)
the union of diverse things into one body or form or group; the growing together of parts	the union of diverse things into one body or form or group; the growing together of parts