www.alphadictionary.com

I recently noticed that the Italian word for battle is Battaglia, and naturally figured a Latin parent, which is battuere, meaning to beat. From there to old French, where we grabbed it.
What is unusual about this word is that the ancient Latin speakers may have borrowed this from Gaulic and not a direct line from PIE.

Touched upon, and perhaps covered, in the Word History of Battery, with another tie in at Battue.

Happy Veterans Day, by the way. That's why I chose this word from all those unanswered posts out there, it's related to the day in a way.