(I think somebody is taking a beginning nav course. Will probably need it if
stepping up from the cartop sail board)

Two references:

From the Dictionary of Nautical Literacy, published by International Marine ( a
division of McGraw-Hill)

Dead reckoning: The process of determining the position of a vessel by tracking
course and speed for a given time.
From the phrase, "deduced reckoning", the plot is called a "DR".

According to this source, Jax is half right. The process is called "dead
reckoning", but the hypothetical plot it produces can be called a "deduced
reckoning."

Then there's another source that indicates neither side of the argument has an
absolute leg to stand on:

From "The Sailor's Illustrated Dictionary"

dead reckoning (DR): The determining of a position by course, speed, and time
elapsed, but without a fix. A DR position is shownon the chart with a half
cirlce and a dot and the time the vessel was calculated to be in the position.
With any other information included, such as wind and current, it is called an
estimated position.
The term "dead reckoning" comes from "deduced reckoning" or "ded. reckoning",
which later became "dead reckoning."

According to this source, the hypotheticaly correct term realy is ded.
reckoning, (short for deduced). Unlike an assertion that anybody who knew squat
about navigation would never say "dead reckoning", those who are exposed to the
practice on an actual basis, in the real world rather than by reading about
boating, have probably never heard the technique called anything
except "dead reckoning."