mannerism vs pretending

mannerism and pretending both are nouns.

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

As nouns, pretending is a hypernym of mannerism; that is, pretending is a word with a broader meaning than mannerism:

Other hypernyms of mannerism include feigning, pretence, pretense, simulation.

mannerism (noun)	pretending (noun)
a deliberate pretense or exaggerated display	the act of giving a false appearance
a behavioral attribute that is distinctive and peculiar to an individual