Thirteen years ago today, back at the dawn of Glossographia, I wrote Five paragraphs on the pentathlon in which I coined the word quinquemation, referring to the elimination of exactly one-fifth of something, an innovation for which I remain desperately under-recognized. The context was the combination of shooting and running into a single event (the excitingly named Laser Run!) in the modern pentathlon, in an act of gross numerical impropriety. But, of course, the analogy is with decimation, the scourge of etymological purists and grammar grouches who insist that it must only mean the destruction of one-tenth of something, rather than (as commonly now) its utter or total destruction. This draws on the misguided principle that a word ought to mean what it means (whatever that means) against the inevitable tide of semantic shift.
And yet! Here we are in 2021 and once again, the modern pentathlon is once again being quinquemated. Now, the discipline of riding is being eliminated after serious problems at the Tokyo Olympics, most notably when a coach punched a horse. Or rather, I suppose it is now a re-quinquemation, leading to the question of whether the new pentathlon will have five events, or four, or three. But it also looks like the UIPM, which governs the sport, is going to try to find a replacement, so the numerical conundrum may be resolved.
In any case, I hereby reassert my right to be recognized as the coiner of quinquemation, a nonce-word that we might have thought would never have another use but has proven its utility once again. You heard it here first … again.
Glossographia 
quinquemation or re-quinquemation, that is not so much a question as evidence (or re-evidence) of your innovation. Fine coinage. As the bull of language stalks the coliseum of things, you are truly a quinquematatdor! (Maybe bullfighting could be the new event?)
Somehow I don’t think that would solve the image problem that the sport is cruel to animals!
Greetings, I’ve just discovered your site and fell upon this entry. You may be pleased to know that there is a French verb ‘requinquer’, meaning to restore or perk up. Perhaps it could be used as an antidote to ‘quinquemation’.