Clamp down Definition 1 of 2Pro Tip 1/3Enforcement Clamp down implies enforcing existing rules more strictly than before. When cheating was discovered, the school clamped down on exam supervision. Pro Tip 2/3Sudden Action It usually refers to a sudden or recent increase in enforcement or control. After the protests, authorities clamped down on public gatherings. Pro Tip 3/3Tight Control The term can carry a negative connotation, suggesting harsh or tight control. The company clamped down on personal phone use, angering employees.