mannerism vs affectedness

mannerism and affectedness both are nouns.

Word	Noun	Adjective	Verb	Adverb
mannerism	Yes	No	No	No
affectedness	Yes	No	No	No

As nouns, mannerism and affectedness are synonyms defined as:

mannerism and affectedness: a deliberate pretense or exaggerated display

Other synonyms of mannerism include affectation, pose.

mannerism (noun)	affectedness (noun)
a deliberate pretense or exaggerated display	a deliberate pretense or exaggerated display
a behavioral attribute that is distinctive and peculiar to an individual	the quality of being false or artificial (as to impress others)