The term 'clamped down on' can be summarized by the word 'bitten', which is a 6-letter word. Bitten is an action verb that means to bite or to pierce with the teeth. It is often used to describe the act of biting someone or something, such as an animal biting a person or a person biting into food. In this context, it implies that someone or something has been forcefully restrained or controlled.