radiancy vs radiance

radiancy and radiance both are nouns.

Word	Noun	Adjective	Verb	Adverb
radiancy	Yes	No	No	No
radiance	Yes	No	No	No

As nouns, radiancy and radiance are synonyms defined as:

radiancy and radiance: the quality of being bright and sending out rays of light

Other synonyms of radiancy include effulgence, refulgence, refulgency, shine.

radiancy (noun)	radiance (noun)
the quality of being bright and sending out rays of light	the quality of being bright and sending out rays of light
	the amount of electromagnetic radiation leaving or arriving at a point on a surface
	an attractive combination of good health and happiness