noun, plural in·sin·cer·i·ties for 2. the quality of being insincere; lack of sincerity; hypocrisy; deceitfulness.

What is insincerity?

: not expressing or showing true feelings : not sincere or honest. Other Words from insincere.

Is communist a noun or adjective?

Communism is a political doctrine that is an extreme form of Socialism, and anyone belonging to this particular political party is called a communist. ... It was first used in English as both a noun and an adjective in 1841, taken from the French communiste.