In Plain English, it means : Go to Hell ! (Harper)

On the 22nd of December 1944, when the division was and had been totally surrounded by the Germans, the intelligence officer and I decided that we had to take this to General McAuliffe. We first took it to the chief of staff, and the three of us, and Colonel Harper then went in, woke up General McAuliffe who was taking a bit of a nap, and told him that we had a surrender ultimatum. And that Tony McAuliffe had first thought that the Germans were trying to surrender to us.

- But, we told him no, not so. That they want us to surrender to them, and they go on to say all the bad things that they’re going to do if we don’t do this.
- Tony McAuliffe then said, “I surrender, ah nuts!”

And then he sort of pondered about whether he should answer or should it be in writing, and so forth.
And everybody agreed that there should be a written answer. Tony McAuliffe then said :

- “Well, I don’t know what to tell them.”
- “Well, what you first said would be hard to beat.”
- “What do you mean ?”
- “You said nuts !”

And all of us in the room sort of thought that was a good answer. So Tony sat down and wrote out with a pencil, “To the German Commander, Nuts ! A. C. McAuliffe, Commanding.” Had his secretary type it out. Gave the message to Colonel Harper, who took it back to his headquarters and gave it to the German Armistice party. The Germans were allowed to take off their blindfold and read the message, and they were puzzled by it. And they were trying to translate nuts. And they said :

- “Nuets ?”
- “Nuets ?”
- “Nuts…?”
- “Wass Is Das ?”

They didn’t get it at all. And Colonel Harper said :

- “If you don’t understand it, it means go to hell!”