The term jiffy (sometimes spelled jiffie) is used for various brief units of time. There is no single ‘correct’ definition but in certain contexts it may be 10 to the power 26 flashes; 1/100th of a second; a heartbeat; or the blink of an eye.
The Jiffy Bag (UK) or Jiffy Mailer (USA) was presumably so called because it was so quick and easy to use.
“I’ll be back in a jiffy...”
The Empire Inn Sign
7 hours ago