In WWI, a nickname for artillery shells. The name was mostly used by the Canadian soldiers.
The trenches may have been eight feet deep, but the men in them never felt safe from the Whizbangs, Minnies, Jack Johnsons, Rum Jars, and Coal Boxes, whose ingenious nicknames masked their deadly purpose.
-Vimy by Pierre Berton
To drive in a recklessyet purposeful manner to gain a better position in any driving situation. When riding a motorcycle, jack moves become involuntary and frequent.
While all of these jack asses were impatiently waiting in far right lane to exit from I-80 to HWY 12, I drove by all of them and bust a jack move at the last second bypassing all traffic.