cynicist
/ˈsɪnɪsɪst/Definitions
1. noun
A person who believes that people are motivated by self-interest and lack of principle, and that life is generally lacking in meaning and value.
“The cynicist in the audience laughed at the politician’s promises of change.”
2. noun
A person who is habitually dissatisfied or scornful, often to the point of being negative or pessimistic.
“He was a cynicist who rarely smiled and often complained about the state of society.”