Went to the range today with one of my ARs. A young lady shooting a bolt gun asked me why I had an "assault rifle." I replied, laughing softly: "Well... just in case someone assaults me! I then explained to her very politely what an "Assault Weapon" really is. Her husband, an Air Force security policeman, joined the discussion on my side! IME, something funny, but polite is a good way to start the discussion, then when the person is comfortable talking to you, you can gradually get more serious. Whatever you do, don't show anger at the misue of the term, or you lose them before you have the chance to educate them.