Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
dead reckoning, dead center, dead right
and many other phrases with dead as the modifier or intensifier have in common either the certainty of death or its precision, exactness, or finality (with no room for adjustment or argument). Dead reckoning locates your ship’s position by using the speed recorded by the log, the time spent on the course, and the compass reading of that course, all adjusted for winds, currents, or tides; all these are numbers, and they permit little guessing or estimating. Dead center is the precise center of something, and if you’re dead right, you are as right as death is certain and irreversible.
