(1). Intensely motivated Martial Arts practitioner. Always working out at the training hall (Dojo).
(2). An old Martial Arts hack that has been around forever and can still kick ass. See dojorat.blogspot.com
(3). All of the above
(2). Tom is an old Dojo Rat dude but he can still crush your face.
(3). I'm scared of those Dojo Rat guys.