ab initio

ab in·​i·​tio | \ ˌab-ə-ˈni-shē-ˌō How to pronounce ab initio (audio) \

Definition of ab initio

: from the beginning

Starting Things With Ab Initio

We'll tell you right from the beginning where ab initio comes from. This adverb was adopted at the beginning of the 17th century directly from Latin, where it translates as "from the beginning." (Initio is a form of the noun initium, meaning "beginning," which gave rise to such English words as initial, initiate, and initiative.) Ab initio most frequently appears in legal contexts, but it is not surprising to find it used outside of the courtroom. The phrase is also used as an adjective meaning "starting from or based on first principles" (as in "predicted from ab initio calculations").

First Known Use of ab initio

1600, in the meaning defined above

History and Etymology for ab initio

Latin ab initiō

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The first known use of ab initio was in 1600

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Cite this Entry

“Ab initio.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ab%20initio. Accessed 26 Feb. 2020.

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ab initio

ab ini·​tio | \ ˌab-ə-ˈni-shē-ˌō, ˌäb-i-ˈnē-tē-ˌō How to pronounce ab initio (audio) \

Legal Definition of ab initio

: from the beginning a contract found to be void ab initio

History and Etymology for ab initio


More from Merriam-Webster on ab initio

Rhyming Dictionary: Words that rhyme with ab initio

Britannica English: Translation of ab initio for Arabic Speakers

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