Four-character acronym stumps internet: 'No idea what it is?'

WD-40 – we've all heard of it, many of us have used it, but most of us wouldn't know what its full name is.

Known by the acronym proudly displayed on the label, it's something most shoppers wouldn't have give a second thought to.

Until a question posed on Twitter left many stumped about what it actually stands for.

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Posting to Twitter, Jason Levin asked: "Without Googling: What does the 'WD' in WD-40 stand for?".

"It's not Western Digital... lol. No idea what it is, but it's not that," said one person.

"Wet dispense?," guesses another. while another joked: "Work dammit!"

And one person suggested: "I don't know what I'm doing so this stuff Will Do."

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The real answer – water displacement, surprised many.

"I was today years old and never knew this," said one person. "Thanks for helping me learn something today," added another.

The product was first created in the US in 1953 as a rust-prevention solvent.

Despite having been around for 70 years, few in the thread knew what the '40' stood for.

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Luckily one person was on hand to explain. "The 40 stands for the number of attempts they tried to make this product and this particular formula was number 40," they said.