What does nanosecond mean?
A nanosecond is a unit of time equal to one billionth of a second, written 10^-9 seconds. It describes durations so short that they are important mainly in specialized scientific, electronic, and computing contexts. For example, processor speeds, data-transfer timing, laser pulses, and chemical reactions may be measured or controlled to nanosecond precision. A nanosecond is much shorter than a microsecond but much longer than a picosecond. The word combines the prefix “nano-,” meaning one billionth, with “second,” the standard unit of time. It is especially useful when discussing systems that must perform or respond with extreme rapidity, and it conveys a more precise measurement than informal expressions such as “instantly.”
nounA unit of time equal to one billionth of a second, or 10^-9 second. A nanosecond is used to measure extremely brief processes in areas such as computing, electronics, and scientific research.
- A unit of time equal to one billionth of a second, or 10^-9 second.
"The new processor can complete each operation in less than a nanosecond."
"The system must respond within a few nanoseconds to maintain accurate timing."
"Researchers measured the reaction with nanosecond precision."
The plural is used when referring to multiple time intervals, measurements, or values.
"The two signals differed by several nanoseconds."
A nanosecond is so brief that light travels only about 30 centimetres in that time.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does nanosecond come from?
The word is formed by combining the prefix nano-, from the Greek nanos meaning “dwarf” and used in modern scientific terminology to mean one billionth, with the unit “second.” The prefix entered international scientific usage through the metric system and the International System of Units, where nanosecond is the standard name for 10^-9 second.
Related word forms
How nanosecond is actually used
Nanosecond is a technical unit used in computing, electronics, physics, chemistry, and other fields where very short intervals of time must be measured or specified. It is normally used in the singular with a numerical value, such as “five nanoseconds,” and in the plural “nanoseconds” when referring to multiple intervals or measurements.
Easily confused with nanosecond
A nanosecond is one billionth of a second, while a microsecond is one millionth of a second; a microsecond is therefore 1,000 times longer.