atto-

combining form

at·​to-
ˈa-(ˌ)tō
: one quintillionth (10−18) part of
attogram

Word History

Etymology

International Scientific Vocabulary, from Danish or Norwegian atten eighteen, from Old Norse āttjān; akin to Old English eahtatīene eighteen

Dictionary Entries Near atto-

attn

atto-

attorn

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Cite this Entry

“Atto-.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/atto-. Accessed 21 Nov. 2024.

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