jerkiness vs unregularity

jerkiness and unregularity both are nouns.

Word	Noun	Adjective	Verb	Adverb
jerkiness	Yes	No	No	No
unregularity	Yes	No	No	No

As nouns, unregularity is a hypernym of jerkiness; that is, unregularity is a word with a broader meaning than jerkiness:

jerkiness: the quality of being spasmodic and irregular
unregularity: not characterized by a fixed principle or rate; at irregular intervals

Other hypernyms of jerkiness include irregularity.

jerkiness (noun)	unregularity (noun)
the quality of being spasmodic and irregular	not characterized by a fixed principle or rate; at irregular intervals