felicity vs radiance

felicity and radiance both are nouns.

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

As nouns, radiance is a hyponym of felicity; that is, radiance is a word with a more specific, narrower meaning than felicity:

felicity: state of well-being characterized by emotions ranging from contentment to intense joy
radiance: an attractive combination of good health and happiness

Other hyponyms of felicity include beatification, beatitude, blessedness.

felicity (noun)	radiance (noun)
pleasing and appropriate manner or style (especially manner or style of expression)	the quality of being bright and sending out rays of light
state of well-being characterized by emotions ranging from contentment to intense joy	the amount of electromagnetic radiation leaving or arriving at a point on a surface
	an attractive combination of good health and happiness