“In February 2009, a Twitter user called @popelizbet issued an apparently historic challenge to someone called Colin: she asked if he could ‘mansplain’ a concept to her. History has not recorded if he did, indeed, proceed to mansplain. But the lexicographer Bernadette Paton, who excavated this exchange last summer, believed it was the first time anyone had used the word in recorded form. ‘It’s been deleted since, but we caught it,’ Paton told me, with quiet satisfaction.

[…]

A few days ago, I emailed to see if ‘mansplain’ had finally reached the OED. It had, but there was a snag – further research had pushed the word back a crucial six months, from February 2009 to August 2008. Then, no sooner had Paton’s entry gone live in January than someone emailed to point out that even this was inaccurate: they had spotted ‘mansplain’ on a May 2008 blog post, just a month after the writer Rebecca Solnit had published her influential essay Men Explain Things to Me. The updated definition, Proffitt assured me, will be available as soon as possible.”

One Wiktionary contributor did a better job[1] in 2012 by immediately finding the use[2] from May 2008. The OED is more Prestigious and Respectable and Authoritative, but the Wiktionary is more comprehensive, informative, reliable, convenient, useful, also cheaper.

[1]: https://en.wiktionary.org/w/index.php?title=Citations:manspl...

[2]: https://web.archive.org/web/20130518221612/http://www.journa...