Where does the phrase "dead simple" originate?

Question

It feels like there should be a story behind it, or perhaps a type of slang, but I can't find anything in various Web searches.

Answer 1

Dead here means utterly, absolutely, which is not a slang usage. Etymonline suggests that it hails from the 14th century, but does not explain whence it derived:

Used from 16c. in adj. sense of "utter, absolute, quite" (cf. dead drunk first attested 1590s; dead heat, 1796). As an adv., from late 14c. Dead on is 1889, from marksmanship.

I would guess the following: death -> permanence -> absoluteness. But this is all speculation. I doubt you'll ever find an authoritative history of this evolution.

Answer 2

In expressions like dead simple, dead easy, dead on, or dead right, dead is used as an adverb, meaning completely or extremely.

Etymonline indicates some of the history:

Used from 16c. in adj. sense of "utter, absolute, quite" (cf. dead drunk first attested 1590s; dead heat, 1796). As an adv., from late 14c. Dead on is 1889, from marksmanship.

Answer 3

Like most confusing idioms it's most likely someone's misunderstanding of a traditional idiom. Dead silent, dead drunk, and dead serious all make sense. Dead silent is because the dead are silent. Dead drunk because you're so drunk you behave like a dead person (falling down, not responding etc.) Dead serious because death is serious. My assumption is another example of people messing up other sayings. Sort of like "walking on egg shells" which was taken from "walking on eggs" which is about not breaking them.

Answer 4

It's very common to use dead meaning very in the north esp. Manchester. I'm Mancunian and I've always thought it came from "dead still" as in "hold completely still don't move", or "it's very quiet", or also "there's no wind at all", knowing how much we like to talk about the weather maybe the last one is the original?

Answer 5

"Dead" in Gaelic means basically "extreme", something like the slang phrase "to the max". So "you're dead right" means "you're extremely right", "dead ahead" means it's directly in front (of a ship's path for example - not even one degree to port or starboard).

The real New York street gang "The Dead Rabbits" (who were re-created in the film "Gangs of New York") got their name because...OK I'm not sure of the spelling, but "rabid" or "rabeed" in Gaelic meant a bad guy, a tough guy, and these extreme tough guys were called "dead rabeeds" by the other Irish immigrants.