Want authoritative definition of "double dare"

By authoritative, I mean just that- Please cite an authority, like a dictionary, not “I always thought it meant…” or “In our school it always meant…”.

This is NOT IMHO, so I don’t care about what you personally mean by it.

For some reason, it doesn’t seem to appear in the on-line dictionaries and glossaries.

Daring someone to answer the question for 4 times the amount, can only be used after being dared.
http://mywebpages.comcast.net/doubledare/rules.htm

Bolding mine.

Greatest kids gameshow ever.

And don’t forget the ultimate rejoinder to the double dare: the double dog dare.

From the Abridged Edition of the Dictionary of American Slang:

v phr by 1940s To challenge provocatively: The movie double-dared its audience to find sympathy in its dour or manic characters --Time/ …I double dog dare ya to find out which three! --Toronto Globe and Mail [fr a boys’ response to “I dare you!”, “I double dare you!”; double dog dare is still higher defiance].

That’s interesting, but I was talking about the phrase, not a game show with the same name. (And we all know how little TV game shows stick to original rules, i.e., they don’t even try; the familiar name is just the hook.)
While the TV show dates from the 70’s, the phrase is much earlier.

There was a big band song in 1938 *I Double Dare You */ by Terry Shand And Jimmy Eaton
And a movie Double Daring (1926).

I’d guess the phrase is much older than those.

**Iluvatar ** - Sorry, you posted while I was composing my answer.

For some reason, I thought that the double was more than a simple intensifier, as in the Dictionary of American Slang version.
Something on the order of “I dare you to do something, and if you won’t then I will.”
The example would be to double dare someone (say an initiate to a group or gang) to do something outrageous. Knock off a policeman’s had, steal an apple as you passed the fruit stand, down a drink in one swig. The idea would be that the newcomer would have to do it, and if complaining it was impossible to be shown up.