To injure or damage someone or something. A noun or pronoun can be used between "bung" and "up." That car accident really bunged my back up. My car is still bunged up from the accident—I really need to take it to the mechanic.

Injured or damaged. My back is still bunged up from that car accident a few months ago My car is all bunged up from the accident—I really need to take it to the mechanic.