Oxford Dictionaries' word of the year is defined as a "significant cultural, political or social change arising from the actions or influence of young people".
The former Vogue editor Diana Vreeland apparently coined "youthquake" in the 1960s to describe the youth culture of Swinging London, and it maintained a modest if somewhat retro currency in conversations about style.
But in the past year, its frequency increased about 400 per cent, according to analysis of the Oxford English Corpus, which collects roughly 150 million words of spoken and written English from various sources each month.
Its usage surged during the coverage of the British parliamentary election in June, when a spike in voting by young people helped deal a blow to the Conservative Party, before spreading to political commentary in New Zealand, Australia, the United States and elsewhere.
Inspired by women's protest marches against the US President, the #MeToo campaign around sexual harassment and the superhero box office hit Wonder Woman, the F word shot to the top of the agenda in 2017, according to Merriam-Webster.
Online searches for feminism were up 70 per cent last year, with interest spiking following several news reports about women's rights, according to the dictionary.
Merriam-Webster defines feminism as "the theory of the political, economic and social equality of the sexes" and "organised activity on behalf of women's rights and interests".
The choice of feminism as word of the year, ahead of "complicit", "recuse" and "empathy", highlights the gains made in a challenging year for women's rights, said campaign groups.
Millions of women have shared stories of sexual abuse on social media with the hashtag #MeToo, sparked by allegations against US movie producer Harvey Weinstein.
3. FAKE NEWS
Derided by US President Donald Trump and accused of influencing elections, "fake news" was Collins Dictionary's word of the year.
It saw an 365 per cent usage increase since 2016, according to Collins, which defines "fake news" as "false, often sensational, information disseminated under the guise of news reporting".
Collins said the association of the word "fake" with "news" started out in the field of comedy - in shows such as Jon Stewart's The Daily Show. But around 2005, the term began to be applied to false news stories that were circulated with malicious intent rather than as satire.
Fast forward to the 2016 US presidential election, and observers noticed large numbers of false stories circulating online about the candidates.
It reached the extent that potentially damaging stories were coined "fake news", and investigations into how these stories proliferate were a big part of the news agenda in 2017.