Means - A person who's a know-it-all and a complete cock. Thinks they have the answers to the universe inside their tiny excuse of a brain. Also think they are above other people because of their smattering of knowledge - hence the "penis".
(n) an highly subjective Urban Dictionary entry that rambles on and on for several pages like a State of the Union address instead of being a concise definition appropriate for this website
Basically the even more uncivilized version of Urban Dictionary. It is hidden in the deep dark evil depths of the internet. God have mercy if you stumble upon this evil.