A number of singers on the Japanese Nico Nico Douga site whose individual versions of the same song have been edited together in such a way that it appears that they are performing the song as one united chorus.
The song is usually (but not always) a vocaloid or anime song with a video backdrop, often with captions and/or icons identifying the individual singers.
Its a noun, that describes the point in time when an individual acts as a chutiya, and an autist at the same time. This godly word combines the two verbs, saving the sayer breath, and causing the hearer to lose a few brain cells.
I was in the public toilets the other day and I let rip, next thing I knew there was a fart chorus going, there was at least another 4 people doing it, we did Britney spears song hit me one more time, we stank though