Photo from expobermuda.com
I believe that tardy actually refers to the behaviour of the Tardis. When the Dr. plots a rough time course, the Tardis rarely gets there, and instead arrives somewhere else, or, if in the right place at a differnt time period. In fact, this is the only consistent behaviour the Tardis can manage. So perhaps the dictionary is wrong, perhaps tardy means “make like a Tardis” and miss your mark! Onwards to Gallifrey, but I guess I’m not going to make it 🙂 Maybe in the next aeon.