Covfefe is the purest exhibit in this series: a word that became world-famous in a few hours while meaning nothing at all.

Six minutes after midnight, Eastern time, on 31 May 2017, President Donald Trump tweeted: "Despite the constant negative press covfefe". The sentence stopped there. The tweet stayed up for about six hours before it was deleted. In its place came a second tweet, asking who could figure out "the true meaning of covfefe".

Nobody could, because none was given. Most news outlets presumed it was a slip for coverage, which fits the sentence. The BBC said that seemed the likely word. Later that day the White House press secretary, Sean Spicer, told reporters that the president and a small group of people knew exactly what he meant. That deepened the mystery without solving it.

Meanwhile, the internet supplied meanings of its own. People argued over how to pronounce it, printed it on T-shirts, and searched for it in other languages. Google Translate identified it as Samoan, the BBC noted, although a reader pointed out that Samoan doesn't use the letter C. Within weeks a member of Congress had introduced a bill named the COVFEFE Act, about preserving presidential social-media posts.

What it never got was a definition. Merriam-Webster's site, in its latest archived check (August 2025), tells you the word isn't in the dictionary. Covfefe is remembered as an event rather than a word: a famous string of letters whose meaning was never found.