Bang up Definition 1 of 3Pro Tip 1/3Colloquial Usage Used in casual conversation, might not be appropriate in formal writing. I can't believe you banged up the van again! Pro Tip 2/3Severity of Damage Implies significant damage, more than just a scratch or dent. After the accident, his bike was completely banged up. Pro Tip 3/3Physical Impact Often suggests a forceful or violent collision with an object. He slipped on the ice and banged up his knee pretty bad.