As a noun, a bludgeon refers to a heavy club used as a weapon. Synonyms for bludgeon include truncheon, nightstick, cudgel, and billy club.
The verb bludgeon developed from the noun form. It means to strike repeatedly with a heavy club or similar weapon. If you have a cockroach invasion in your kitchen, you might be tempted to bludgeon the insects with a rolled up newspaper every time you turn on the lights. The verb bludgeon is also used metaphorically to mean to roughly coerce or force someone to do something as if you had a bludgeon. If your boss is a bully, he may bludgeon you and the other employees into working long hours for little recognition.