Clamp1  —n. 1 device, esp. A brace or band of iron etc., for strengthening or holding things together. 2 device for immobilizing an illegally parked vehicle. —v. 1 strengthen or fasten with a clamp; fix firmly. 2 immobilize (a vehicle) with a clamp.  clamp down (usu. Foll. By on) become stricter (about); suppress. [low german or dutch]