Frown

He noticed a deep frown on her face as she struggled to solve the math problem.

The politician's frown during the debate showed his disagreement with his opponent's statement.

The news of the impending storm caused a collective frown among the residents.

The artist's frown showed her dissatisfaction with the final brushstrokes on her painting.

The detective's frown suggested that he had encountered a puzzling clue in the crime scene.