An event that is the result of one becoming very excited (be it positive or negative excitement) whilst typing, resulting in one sending a random (usually long) string of random letters and/or characters caused by randomly mashing buttons on one's keyboard--hence the name. These are a common occurance in online conversations (i.e. IMing, Facebook, ect.) and text messages.
Example 1 (negative anger/frustration):
Kaitlyn: OMG, L just died on Death Note!
Ryan: bdjbsdbjhsdbdhdb OMG NO. ;A;
Kaitlyn: ......it's just a show, no need in keymashing on me.

Example 2 (positive excitement):
Damon: Yobanashi Deceive came out today!
Samantha: kmklmoninnninipiihj''mk I MUST HAVE IT!!!!! <3
Damon: O-o Judging by that keymashing you were doing, I should say so...
by Nagito Komaeda May 22, 2013
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When one snaps and start mashing the fucking keyboard, which results in usually typing random string of letters and/or symbols whilst destroying your keyboard.
Example of a message that could be written while committing a mad keymash:

" CVVG H H NT gvf53 E ATRGR AWRF DasdfED53 WS4N6 K53E54 5asfa 2 65E3"
by LeoKaro219 June 28, 2022
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The result of randomly (or not-so-randomly) mashing one’s keyboard to signify laughter or shock. Most prominently seen in queer Generation Z online culture.
this website says I’m the same personality type as Flowey and Twitter lmao”
“FDSKJFFJK THE ENTIRETY TWITTER;;”
“yes lol nice gay keymash”
by Hogtrude Parker December 2, 2021
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