unprecedented
Americanadjective
adjective
Other Word Forms
Etymology
Origin of unprecedented
Explanation
Something that is unprecedented is not known, experienced, or done before. If you've never gone on a family beach vacation but you're planning one now, you could refer to it as an unprecedented decision. The root of this word is precedent, a noun referring to something done or said that is used as an example to be followed in the future. In law, a precedent is a legal decision that is used as a standard in future cases. So the adjective unprecedented, meaning "having no precedent," was formed from the prefix un- "not," the noun precedent, and the suffix –ed "having."
Vocabulary lists containing unprecedented
The SAT: Words to Capture Tone, List 5
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The New SAT: Words to Capture Tone
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Fast Food Nation
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Three people were recently hospitalized after eating poisonous wild mushrooms foraged in California wine country amid an unprecedented outbreak of illness and deaths linked to the practice statewide, health officials in Napa County announced.
From Los Angeles Times • May 15, 2026
However, “it’s unprecedented in that Trump is on both sides of the settlement,” Sheil told me.
From Slate • May 15, 2026
Since launching in 2003, the spacecraft has spent more than 20 years studying the Red Planet and mapping its surface in color and in three dimensions at unprecedented detail.
From Science Daily • May 15, 2026
The CDC reported an over-2% decline in drug-overdose deaths between 2022 and 2023, an unprecedented nearly 27% decline between 2023 and 2024 and now a nearly 14% decline between 2024 and 2025.
From The Wall Street Journal • May 13, 2026
The Ministry of Magic consented to this unprecedented release to raise money for Comic Relief, a well-respected Muggle charity.
From "Fantastic Beasts and Where to Find Them" by J.K. Rowling
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
