littleness vs pettiness

littleness and pettiness both are nouns.

Word	Noun	Adjective	Verb	Adverb
littleness	Yes	No	No	No
pettiness	Yes	No	No	No

As nouns, littleness and pettiness are synonyms defined as:

Other synonyms of littleness include smallness.

littleness (noun)	pettiness (noun)
the property of having a relatively small size	the quality of being unimportant and petty or frivolous
lack of generosity in trifling matters	lack of generosity in trifling matters
the property of having relatively little strength or vigor	narrowness of mind or ideas or views