unprecedented
adj.adj. never done or known before. You use this to describe something that is completely new or happens on a scale that has never been seen in the past.
adj. having no previous example or parallel in history. Often used to describe the scale, speed, or nature of a significant event that lacks a historical equivalent.
The city is facing an unprecedented heatwave this summer.
The government took the unprecedented step of closing all borders to prevent the spread of the new virus.
The rapid integration of artificial intelligence into daily life represents an unprecedented shift in how humans interact with technology, challenging existing legal and ethical frameworks.
From un- + precedent + -ed.
Typically used to modify nouns representing events, changes, or levels of growth.