K to the C's definitions

jack johnson

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

by K to the C October 24, 2006