capriciousness vs inconstancy

capriciousness and inconstancy both are nouns.

Word	Noun	Adjective	Verb	Adverb
capriciousness	Yes	No	No	No
inconstancy	Yes	No	No	No

As nouns, inconstancy is a hypernym of capriciousness; that is, inconstancy is a word with a broader meaning than capriciousness:

capriciousness: the quality of being guided by sudden unpredictable impulses
inconstancy: the quality of being changeable and variable

Other hypernyms of capriciousness include changefulness.

capriciousness (noun)	inconstancy (noun)
the trait of acting unpredictably and more from whim or caprice than from reason or judgment	the quality of being changeable and variable
the quality of being guided by sudden unpredictable impulses	unfaithfulness by virtue of being unreliable or treacherous