meanness vs littleness

meanness and littleness both are nouns.

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

As nouns, littleness is a hyponym of meanness; that is, littleness is a word with a more specific, narrower meaning than meanness:

Other hyponyms of meanness include pettiness, smallness, miserliness.

meanness (noun)	littleness (noun)
the quality of being deliberately mean	the property of having a relatively small size
extreme stinginess	lack of generosity in trifling matters
	the property of having relatively little strength or vigor