jiffy

noun

Etymology: Origin unknown; said to have been thieves’ cant for “lightning”. Also formerly written "giffy", to which a connection with gliff has been proposed. As a kind of envelope, a genericization of Jiffy bag.

1. A very short, unspecified length of time.

   “I’ll be back in a jiffy.”

   “Most of the limbs of the law do every thing in a jiffy; but ask what they mean, and they would be as much puzzled, as if you required of them the explanantion of a common act of parliament.”

2. A unit of time defined by the frequency of its basic timer – historically, and by convention, 0.01 of a second, but some computer operating systems use other values.

   “The FOR...NEXT loop for TIME increments by STEP 2 (every two jiffies) for two reasons: 1) the printing of 60 jiffies a second is too fast to read, and 2) the printing of each jiffy takes longer than its incrementations; this would delay the loop, so the printing of TIME$ is slower than it should be.”

   “The number of processed packets per round is limited in dependence of the page size. The processed packets are forwarded to a single queue and are processed for the time of two jiffies.”

3. The length of an alternating current power cycle (1/60 or 1/50 of a second).
4. The time taken for light to travel a specified distance in a vacuum, usually one centimetre (approximately 33.3564 picoseconds), but sometimes one foot or the width of a nucleon.
5. Ellipsis of jiffy bag, a padded envelope.