Not for the first time, a Donald Trump tweet has lit up the internet. But this time, users the world over have been left scratching their heads over "covfefe": a bizarre word apparently created by the president.
"Despite the constant negative press covfefe," read the US leader's short tweet sent early Wednesday.
Was it an acronym? A secret message? Or just a typo?
Wags around the world weighed in with biting sarcasm, and #covfefe quickly became the top trending item on Twitter.
Comments included a mock Google translation of "covfefe" from Russian into English as "I resign," and comments like "Drain the covfefe" -- a play on Trump's promise to "drain the swamp" in Washington.
"'Covfefe is a great word, period! - Sean Spicer tomorrow," read one tweet, mentioning the president's spokesman.
To avoid confusion, the Regent's English Language Center in London wrote: "To all of our English language students, we can confirm that 'covfefe' is not an English word. Yet."
At 0910 GMT Trump's "covfefe" tweet had more than 120,000 retweets and had been shared 39,000 times, according to Twitter figures.
Then, around 0945 GMT, more than five hours after it was posted, the mysterious tweet vanished.
Soon after Trump himself joined the deciphering game. "Who can figure out the true meaning of "covfefe" ??? Enjoy!" he tweeted, in an unusual display of self-depreciating humor.
Since entering office, Trump has used Twitter to issue declarations on everything from Arnold Schwarzenegger's TV performance to an alleged "MASSIVE trade deficit with Germany."