Dating to at least 1785, the term “jiffy” is used informally to refer to any unspecified short period of time, often the brief moment it will take to finish a task. Certain fields of science use the word technically to denote a specific unit of time—typically a fraction of a second. In electronics, for example, a jiffy is defined as the time between alternating current power cycles. In computing, a jiffy is the duration of one tick of the system timer interrupt. What is a jiffy in astrophysics? Discuss
Source: The Free Dictionary