"Goes back to bed", @MerriamWebster wrote after Trump's first tweet ignited a slew of possible definitions and jokes, as well as defences of the president.
The response prompted the LIRR to delete the tweet, said spokesman Aaron Donovan.
From the candidate who gave us "bigly" at a presidential debate, now comes "covfefe" in a midnight tweet from the White House.
A NY driver claimed the personalized license plate bearing the letters "COVFEFE" a little more than an hour after Trump tweeted the "word" from his Twitter account after midnight Wednesday, only to remove the tweet six hours later.More news: Kathy Griffin says she's receiving death threats
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Spicer tells reporters when asked about the tweet: "I think the president and a small group of people know exactly what he meant". But this time, users the world over have been left scratching their heads over "covfefe": a freakish word apparently created by the president. Check out the "covfefe" tweets below.
"We are focused on the president's agenda", White House press secretary Sean Spicer answered. Now I own the EU-wide rights to what is maybe the world's most talked-about word right now.
Trump was relatively quiet on Twitter during a nine-day trip to Middle East and Europe but resumed tweet storms after returning home on Saturday. And, for one brief moment, the internet was united in its total fascination with that one odd not-even-really-a-word word. "You don't have a high enough classification to know what covfefe means".
Or perhaps, it was his jibe at Trump critics who has unleashed endless waves of mockery with their wild guesses of its meaning.
The presumably made-up word ended up trending on social media, with memes galore and "covfefe" merchandise for sale.