Jack
informal
informal
used to typify an ordinary man.
"he had that world-weary look of the working Jack who'd seen everything"
USinformal
used as a form of address to a man whose name is not known.
NORTH AMERICANinformal
a lumberjack.
a detective or police officer.
archaic
a steeplejack.
the figure of a man striking the bell on a clock.