Sophomoric (adjective)

1. Conceited and overconfident of one's own intelligence or knowledge, especially when such confidence is unjustified.
2. Conceited and overconfident of one's own intelligence or knowledge.

Origin:

From sophomores + -ic.

Examples:

1. The sophomore's sophomoric behavior was not well received by the upperclassmen.
2. The student's sophomoric attitude was a hindrance to his classmates.
3. The writer's sophomoric style was not well received by the critics.
4. The politician's sophomoric rhetoric was often criticized.
5. The actor's sophomoric performance was not well received by the audience.