Is disingenuousness a word?

Lack of sincerity: ambidexterity, artificiality, insincerity, phoniness.

What does it mean if something is pretentious?

a : making usually unjustified or excessive claims (as of value or standing) the pretentious fraud who assumes a love of culture that is alien to him— Richard Watts. b : expressive of affected, unwarranted, or exaggerated importance, worth, or stature pretentious language pretentious houses.