Her constant talk about artworks she knew nothing about at the party was pure pretentiousness.

pretentiousness 是由形容词 pretentious 加上名词后缀 -ness 构成的名词。pretentious 来自动词 pretend（假装），pretentious 意思是"装模作样的、自命不凡的"。pretentiousness 指"装腔作势、矫揉造作的行为或特质"。