"Post-truth has gone from being a peripheral term to being a mainstay in political commentary," the Oxford Dictionaries said in a statement, noting that usage had increased by 2,000 per cent since last year.
The publisher defined the word as "relating or denoting circumstances in which objective facts are less influential in shaping public opinion than appeals to emotion and personal belief".
"It's not surprising that our choice reflects a year dominated by highly-charged political and social discourse," said Casper Grathwohl, president of Oxford Dictionaries.
"Fuelled by the rise of social media as a news source and a growing distrust of facts offered up by the establishment, 'post-truth' as a concept has been finding its linguistic footing for some time.
"We first saw the frequency really spike this year in June with buzz over the Brexit vote and again in July when Donald Trump secured the Republican presidential nomination."
The runners-up for words of the year included the British term "Brexiteer" used for anti-EU advocates.
"Alt-right" also made the shortlist, defined as an ultra-conservative grouping in the United States "characterized by a rejection of mainstream politics and the use of online media to disseminate deliberately controversial content".
Trump's appointment of anti-establishment media firebrand Steve Bannon, seen as a leader of the "alt-right" movement, as his chief of staff earlier this week has proved highly controversial.
The Oxford Dictionaries said the word "post-truth" had become "overwhelmingly" associated with politics.
"Given that usage of the term hasn't shown any signs of slowing down, I wouldn't be surprised if 'post-truth' becomes one of the defining words of our time," Grathwohl said.
The publisher traced the first use of the word to a 1992 essay by late Serbian-American playwright Steve Tesich in The Nation magazine about the Iran-Contra scandal and the Gulf War.
"We, as a free people, have freely decided that we want to live in some post-truth world," Tesich wrote.
"There is evidence of the phrase 'post-truth' being used before Tesich's article, but apparently with the transparent meaning 'after the truth was known' and not with the new implication that truth itself has become irrelevant," Oxford Dictionaries said.
Published : Aug 14, 2022
Published : November 16, 2016
By : Agence France-Presse