noun. One billionth (10⁻⁹) of a second.

noun. A measure of time equal to one billionth of a second. Abbreviation: ns

noun. one billionth (10^-9) of a second; one thousandth of a microsecond

"** Though a nanosecond has a technical definition as a millionth of a second, PT has always been partial to the folk definition: A nanosecond is the length of time between when the light in front of you goes green and the car behind you honks its horn."

time unit  unit of time  

Angstrom  antiship  blue-violet  circularly-polarized  ground/vehicle