at·​to·​sec·​ond | \ ˈa-(ˌ)tō-ˌse-kənd How to pronounce attosecond (audio) , -kənt \

Definition of attosecond

: one quintillionth (10−18) of a second An attosecond is to a second what a second is to the age of the universe.IEEE Spectrum

Examples of attosecond in a Sentence

Recent Examples on the Web Not a lot: a clock needs to be accurate to within a few attoseconds (10-18s) to be able to detect centimeter differences in height. Chris Lee, Ars Technica, 13 Apr. 2020 Researchers have created light pulses lasting just 53 attoseconds using high-speed lasers. David Labrador, Scientific American, 25 Jan. 2012

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'attosecond.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of attosecond

1962, in the meaning defined above

History and Etymology for attosecond

atto- + second entry 4

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The first known use of attosecond was in 1962

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Cite this Entry

“Attosecond.” Dictionary, Merriam-Webster, Accessed 3 Aug. 2021.

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