ungracefulness vs clumsiness

ungracefulness and clumsiness both are nouns.

Word	Noun	Adjective	Verb	Adverb
ungracefulness	Yes	No	No	No
clumsiness	Yes	No	No	No

As nouns, clumsiness is a hypernym of ungracefulness; that is, clumsiness is a word with a broader meaning than ungracefulness:

ungracefulness: an unpleasant lack of grace in carriage or form or movement or expression
clumsiness: the carriage of someone whose movements and posture are ungainly or inelegant

Other hypernyms of ungracefulness include awkwardness.

ungracefulness (noun)	clumsiness (noun)
an unpleasant lack of grace in carriage or form or movement or expression	the carriage of someone whose movements and posture are ungainly or inelegant
	the inelegance of someone stiff and unrelaxed (as by embarrassment)
	unskillfulness resulting from a lack of training