A Danish and corrupted translation of the word fuckboy but more used in a fun way rather than in all seriousness unlike it's English translation; fuckboy.
When one smokes enough weed to start hearing out of their knees.
"Yo guys shut the f*ck up!!!" -Kneeboy
"What's wrong?!" -Franco "I'm hearing out of my knees!!!" -KB
*KB falls over from room getting too loud of laughter"