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Leftover dried cum on a blanket, pillow or a girls face.
Could be an insult, meaning migher or something along those lines.
"Dude! i came on her face last night and there was roobknob leftover this morning.... i guess she didn't clean it all off.."

"That kid looks like such a roobknob, hes running around naked wow."
by salmandralphd October 22, 2009
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