This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

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• Wordscraper
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n. One billionth (10-9) of a second.

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

n. 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   

ultrashort    tight-beam    circularly-polarized    Angstrom    nanometer    blue-violet    ground/vehicle    microsecond    point-defense    millisecond