Definition of "unprecedented"

With the descent of the cold war, relations between the two countries (for this is, to all intents and purposes, what they became after the end of the war) were almost completely broken off, with whole families split for the ensuing decades, some for ever. This event and its after-effects, along with the war against the Japanese in the 1940s, was to cast a long shadow over the years ahead, and led to the creation of the wholly unprecedented worship of Kim Il-sung, and his elevation to almost God-like status. It was also to create the system in which his son was to occupy almost as impossibly elevated a position.

2011 December 19, Kerry Brown, “Kim Jong-il obituary”, in The Guardian‎

On October 6, 1927, Warner Bros. released The Jazz Singer, the first sound-synched feature film, prompting a technological shift of unprecedented speed and unstoppable force. Within two years, nearly every studio release was a talkie.

2012, Christoper Zara, Tortured Artists: From Picasso and Monroe to Warhol and Winehouse, the Twisted Secrets of the World's Most Creative Minds, part 1, chapter 1, 27