What does "insincerity" mean?

Insincerity: The quality of being insincere; want of sincerity, or of being in reality what one appears to be; dissimulation; hypocritical; deceitfulness; hollowness; untrustworthiness; as, the insincerity of a professed friend; the insincerity of professions of regard. What men call policy and knowledge of the world, is commonly no other thing than dissimulation and insincerity. Blair.