dead reckoning

Etymology
. Not short for or, but this belief explains the alternative spelling  (which actually originated centuries later).

Noun

 * 1) A method of estimating the position of a ship or aircraft by applying estimates of the distance and direction travelled from a previously known position. In respect to ships/boats, it excludes the effect of wind and current on the vessel. Compare with estimated position. Abbreviation: DR

Translations

 * Dutch: gegist bestek
 * Finnish: merkintälasku
 * French: navigation à l'estime
 * Greek: νεκρός απολογισμός
 * Polish: nawigacja zliczeniowa
 * Portuguese: navegação estimada
 * Spanish:
 * Swedish: död räkning