phraseology: dead reckoning

If this were a magazine or some kind of legit periodical I would probably call this the start of a new 'column' or 'feature'. I write a lot and I enjoy hearing new and interesting phrases. I kind of collect them, I suppose. For titles of stories or to pepper in conversation or whatever. Never know when you might need a new phrase. I also like finding out their origin, because if I understand it, I'll remember it and know how to use it.

So from time to time I think I'll post new phrases I encounter and find interesting. For my purposes, I'll refer to memes and terms as phrases. In addition, I have a thing for neologisms, which Wikipedia defines as

a newly coined word that may be in the process of entering common use, but has not yet been accepted into mainstream language

Anyway, my latest phrase discovery, if you haven't already guessed from the title of this post, is

dead reckoning

Kind of rolls of the tongue and curls up in your ear, doesn't it? It sounds biblical. It sounds, well, serious like death is serious. Might make a good episode title of some future show. Might not. According to Wikipedia, 'dead reckoning' is

the process of estimating one's current position based upon a previously determined position, or fix, and advancing that position based upon known or estimated speeds over elapsed time, and course.

Basically, navigating that relies on knowing where and how far you've gone since the last time you knew where you were. Not based on, say, the stars in the sky or somesuch. There are two accounts of where this comes from. One is that it is short for 'deduced reckoning', which is pretty straightforward. The other is that stellar navigation is considered 'live', so not relying on the stars would be 'dead'.

It's also the name of a Humphrey Bogart film, two separate bands, and the original title for Land of the Dead.