Definition of "jiffy" in English

noun

1. (colloquial) A very short, unspecified length of time.

   • I’ll be back in a jiffy.

2. (computing) 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.

3. (electronics) The length of an alternating current power cycle (1/60 or 1/50 of a second).

4. (physics) 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. (UK) Ellipsis of jiffy bag, a padded envelope.