The British dictionary publisher defines "youthquake" as "a significant cultural, political or social change arising from the actions or influence of young people."
Even Casper Grathwohl, the publisher's president of dictionaries, admitted it was "not an obvious choice."
"Many of you may even be scratching your heads," Grathwohl said in a blog post. And indeed, the selection was met with some puzzlement on Twitter.
(Story continues below.)
Grathwohl claims that usage of the term, coined in 1965, soared fivefold in 2017 when compared with the previous year.
Its rising profile followed the United Kingdom's general election in June, he said, when younger voters were credited with helping Prime Minister Theresa May lose her Conservative Party's majority in the House of Commons.
Grathwohl also had this to say about "youthquake's" ultimate selection for the accolade:
Sometimes you pick a word as the Word of the Year because you recognize that it has arrived, but other times you pick one that is knocking at the door and you want to help usher it in.
Other terms that made the final shortlist included antifa, broflake, gorpcore, kompromat, milkshake duck, newsjacking, unicorn and white fragility.