A jiffy is a measurement of time

I have always known that the term, 'back in a jiffy' means, 'I will return in a short amount of time.' However I have always just assumed that it was a saying, something somebody had made up at some point that had caught on, a bit like the Yellow Pages ad in Australia, where the woman shouts out her window at her receptionist, who forgot to put the business' number in the Yellow Pages directory, 'Not happy Jan.' However today I learnt that a jiffy is actually a measurement of time. A jiffy, as defined by Gilbert Newton Lewis, an American physical chemist, is the time it takes light to travel one centimetre. As light travels quickly, the time it would take to travel one centimetre would not be long, so it fits with the meaning of the saying 'back in a jiffy.'

According to Wikipedia however, the above definition is not the only definition for a jiffy, as it has different meanings when used referring to computing or electronics. It is also unclear whether the term jiffy was used before Lewis' definition was created (Lewis' definition was recorded as being created before any other definition). Considering that all the official definitions of jiffy define things that occur quickly, usually within one or two seconds, which fits with the theme 'back in a jiffy' referring to a short amount of time elapsing, it could be that the word jiffy was made up to mean a short amount of time and then adopted to officially define things after the word came into popular use. If this is true then I have hopes that one day my word, 'Regimimer' pronounced reg-e-mimer, which means an 'aggressive young go-getter', will one day become widespread in use!

Read more about a jiffy on Wikipedia.