unprecedented

The word “unprecedented” means never having happened or been seen before. In plain terms, so new or extreme that nothing like it has happened before.

“Unprecedented” is pronounced uhn-PREH-sih-dehn-tihd (/ʌnˈpɹɛsɪdɛntɪd/ in IPA).

Here is “unprecedented” used in a sentence: “The storm caused unprecedented flooding across the region.”

“Unprecedented” is an adjective.

“Unprecedented” is a fairly common word in modern English.

Unprecedented means something has never happened or been seen before at all, making it entirely without prior example. Rare means something happens infrequently but has occurred before. An unprecedented event is by definition rarer than a rare one, since it has no known predecessor.

Unprecedented focuses on something never having happened before in history or record, often used for events, decisions, or crises. Unique focuses on something being one of a kind at present, without necessarily comparing it to the past. A situation can be unique without being historically unprecedented.

Unprecedented is frequently used to describe extreme events, records, or situations, such as unprecedented growth, unprecedented demand, or an unprecedented crisis. It signals that the scale or nature of the event has no known earlier equivalent.