A “youthquake” is aocial, cultural, or political change brought about by young people. In politics, it is typically used to mean a surge of young voters in a key election.
The term originated in the fashion industry in 1965, when it was used by Vogue magazine. It has taken on a more politically charged meaning in recent years, and was voted the ‘Word of the Year’ for 2017 by Oxford.
The Guardian: ‘Youthquake’ Behind Labour Election Surge Divides Generations