A clamp is a device that holds two things firmly together.

When you clamp one thing to another, you fasten the two things together with a clamp.

To clamp something in a particular place means to put it or hold it there firmly and tightly.

A clamp is a large metal device which is fitted to the wheel of an illegally parked car or other vehicle in order to prevent it from being driven away. The driver has to pay to have the clamp removed.

To clamp a car means to fit a clamp to one of its wheels so that it cannot be driven away.