slowness vs clumsiness

slowness and clumsiness both are nouns.

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

As nouns, slowness and clumsiness are synonyms defined as:

slowness and clumsiness: unskillfulness resulting from a lack of training

Other synonyms of slowness include awkwardness, ineptitude, ineptness, maladroitness.

slowness (noun)	clumsiness (noun)
a rate demonstrating an absence of haste or hurry	the carriage of someone whose movements and posture are ungainly or inelegant
lack of normal development of intellectual capacities	the inelegance of someone stiff and unrelaxed (as by embarrassment)
unskillfulness resulting from a lack of training	unskillfulness resulting from a lack of training