snickerer
/ˈsɪknərər/Definitions
1. noun
A person who smirks or laughs in a sneering or scornful manner.
“The snickerer in the back of the classroom made it hard for the teacher to focus on the lesson.”
2. verb
To laugh or smile in a sneering or scornful manner.
“The kids snickered at the silly joke their friend told.”