音标: [ʌnˈpresɪdentɪd]

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.”

This is a day of unprecedented triumph… for the Russian space program and a crushing blow for America in the race for space.

Dial it back, officer. This situation is unprecedented.

lt’s unprecedented.

That would be unprecedented.