Dictionary.com
Thesaurus.com
Showing results for unprecedented. Search instead for unprecedented moments.
Synonyms

unprecedented

American  
[uhn-pres-i-den-tid] / ʌnˈprɛs ɪˌdɛn tɪd /

adjective

  1. without previous instance; never before known or experienced; unexampled or unparalleled.

    an unprecedented event.

    Synonyms:
    novel, exceptional, extraordinary, unique

unprecedented British  
/ ʌnˈprɛsɪˌdɛntɪd /

adjective

  1. having no precedent; unparalleled

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

Derived Forms

Etymology

Origin of unprecedented

First recorded in 1615–25; un- 1 + precedent + -ed 2

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."

Keep Reading on Vocabulary.com

Vocabulary lists containing unprecedented

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.

"What has happened is quite unprecedented," says Dwaipayan Bhattacharyya, a political scientist.

From BBC • Jun. 8, 2026

The tensions between the U.S. and Israel are becoming a defining characteristic of the current phase of the war, much as unprecedented close cooperation between the two allies marked its beginning.

From The Wall Street Journal • Jun. 8, 2026

Pope Leo XIV will give an unprecedented address on Monday to the Spanish parliament and is set to meet with victims of sexual abuse by clergy.

From Barron's • Jun. 8, 2026

Anthropic and OpenAI will join SpaceX at the US mega-corp top table – exerting hitherto unseen power and influence across the globe and unprecedented dominion over its citizens if its champions are to be believed.

From BBC • Jun. 8, 2026

Things started out decorously enough but deteriorated into unprecedented pandemonium.

From "The Evolution of Calpurnia Tate" by Jacqueline Kelly

Vocabulary.com logo
by dictionary.com

Look it up. Learn it forever.

Remember "unprecedented" for good with VocabTrainer. Expand your vocabulary effortlessly with personalized learning tools that adapt to your goals.

Take me to Vocabulary.com