coalescence vs coalescency

coalescence and coalescency both are nouns.

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

As nouns, coalescence and coalescency are synonyms defined as:

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

Other synonyms of coalescence include coalition, concretion, conglutination.

coalescence (noun)	coalescency (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