The state one's in when they're attempting to watch only one video on YouTube, but due to the suggestions on the side, cannot stop themselves from clicking more videos. One video turns to two, which then leads to 20, 30 or even more...

Once you surpass your eighth video (completely arbitrary) you're officially in a "YouTube wormhole."

The process of leaving the wormhole comes from either the want of food, drink or you desperately having to use the bathroom.
"Where've you been all day?"

"A YouTube wormhole."
by che-LDN August 18, 2013
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