jiffy

2. A very brief moment used informally to mean 'soon' or 'quickly'.

She finished her homework in a jiffy.

3. In physics and engineering, a jiffy is a specific unit of time used in computing or signal processing.

The signal delay was measured in jiffies.

4. In electronics, a jiffy can refer to one cycle of alternating current (about 1/60 of a second in the US).

The old timer measured the pulse in jiffies.