jiffy

Jiffy is a term with several distinct uses in English. Most commonly, it denotes a very short period of time, as in the idiom “in a jiffy.” The origin is uncertain, but the term has been used since at least the 19th century to mean a moment or brief interval.

In computing, a jiffy is a unit of time corresponding to one tick of the system timer interrupt. The exact length depends on the operating system’s timer frequency, often described by the HZ value. In Linux and other Unix-like systems, jiffies are a counter that increments with each timer tick and track the elapsed time since boot; 1 jiffy equals 1/HZ seconds.

The word also appears as a brand name in consumer products. Jiffy is known for baking mixes, especially corn muffin mix, sold under the Jiffy brand in North America. The brand name is used for a range of quick-bread and cake mixes.

In addition to these uses, the phrase “in a jiffy” is common in everyday English to indicate performing something quickly.