Meaning of phrase

[CWUGWENT]

Can any help please, Where did the saying "in a jiffy" originate from?

Many thanks in advance

[Quizmonster]

The earliest recorded use of 'jiffy' to mean a moment was from the 1780s, but no one knows its origin.

[Quizmonster]

There is, apparently, a belief that it started as thieves' slang meaning 'lightning' - according to an American dictionary - but no real evidence to support that.

[Quizmonster]

Oh, I forgot about the modern scientific use of the word. Nowadays, it seems to have been taken over by scientists in the worlds of electronics, physics, computing etc who use it to mean various time-periods. These vary in length from about 33 picoseconds - ie 0.000,000,000,033,300 seconds - for physicists to about 1/50th - ie 0.02 of a second for electronics engineers.
(Basically, unless you happen to be one of these scientists, I'd just forget the modern interpretation they have chosen to put on the word, if I were you!)

[SKA]

is it jiffy as in a jiffy bag?

[Quizmonster]

'Jiffy', as in 'jiffy bag' is simply part of a trade name, created by the Jiffy Packaging Company of Winsford in Cheshire and first produced in the 1960s. As such, it is similar to 'hoover', meaning any such cleaning-machine and written now with a lower-case opening letter, just as 'jiffy-bag' now is.

[Postdog]

There were also Jiffy condoms. I'll say no more, eh....!