A bash is a party or celebration, especially a large one held by an official organization or attended by famous people.

If someone bashes you, they attack you by hitting or punching you hard.

If you bash something, you hit it hard in a rough or careless way.

If you get a bash on a part of your body, someone or something hits you hard, or you bump into something.

To bash someone means to criticize them severely, usually in a public way.

If you have a bash at something, you try to do it.