A Zulu is a strip dance while on the table, and everyone sings the Zulu around the table... when you are down to your birthday suit everyone applauds you by throwing beer over you.
I only done it once while I was in the RAF... just as they threw the beer over me, the officers wives walked in.........I nearly broke me neck diving under the table. The Airmans wives thought it was hysterical.................My Commanding Officer thought otherwise..........oops.