n.an
instrument that continuously records on a piece of paper the positions of a
ship based on
dead reckoning (the calculation of a
vessel's
approximate position on the basis of compass readings, speed, and distance sailed through the water from a known
point).
Dead reckoning is
thought to have originally been called "
deduced" reckoning, which was shortened to "
ded," (or "
dead") reckoning.