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Ask HN: What happened to 'effusive' in 1866?
If you do a Google search for 'effusive', and then click on 'Translations, word origin, and more definitions' you see the start of a hockey stick graph while 'effusive' gets users.
https://www.google.com/?gws_rd=ssl#q=effusive
What happened in 1866 that made this word popular? And why did growth hit a plateau around 1900?
Is there something we could learn about virality just by studying word popularity?