insouciance vs lightheartedness

insouciance and lightheartedness both are nouns.

Word	Noun	Adjective	Verb	Adverb
insouciance	Yes	No	No	No
lightheartedness	Yes	No	No	No

As nouns, insouciance and lightheartedness are synonyms defined as:

insouciance and lightheartedness: the cheerful feeling you have when nothing is troubling you

Other synonyms of insouciance include carefreeness, lightsomeness.

insouciance (noun)	lightheartedness (noun)
the cheerful feeling you have when nothing is troubling you	the cheerful feeling you have when nothing is troubling you