What constitutes a dangerous weapon?

In Massachusetts, apparently a pumpkin does. A woman has been charged with assault and battery with a dangerous weapon, that weapon being a pumpkin. And the police have secured that weapon in a police locker until her case is resolved. Hope they've taken lots of photos of the weapon - my guess is that it won't be in quite the same condition after a few months in lockup, and it will no longer be the terrifyingly dangerous weapon it is today.