[Andoryuuta]

I love words like this that have slang meanings that are basically the complete opposite meaning. Very similar to slang usage of "sick", "gnarly", "crazy", "insane", etc in (American?) English.

I'm choosing to believe that the egui (library) name is the "positive egui" form[0]. ;)

[0]: https://unseen-japan.com/egui-japanese-meaning-change/

[deaddodo]

That's more California slang than American. Although it's pretty widely spread/known simply via cultural/linguistic osmosis.