A disorder that affects many teenagers across the globe. It is named for JpopYuna, an overweight teenager who is known for her horrible singing voice and countless jpop covers.

It is the desire to sing every song ever produced by the Japanese Pop industry and upload the tracks to youtube, regardless if you can actually sing them or not.

Those affected usually have really horrible singing voices, an inability to count beats and keep time, naturally making their covers of songs really painful to listen to.

JpopYuna Syndrome usually affects those who are depressed, stubborn, and tone deaf.

Adj. Something that is expected to have a long lifespan by virtue of having existed for a long time, based on the lindy effect, named for the New York restaurant Lindy's, coined by Albert Goldman and popularized by Nassim Taleb.