Belong to the same family as mongoloid and bongloid, a gongloid refers to a guy who is at least 19 or 20 years old, but still threatens to tell on other people for doing things we he believes to be against the rules. One trait is that he will pretend to be taking a shit in the restroom, but when somebody opens the door to take a picture of him he is actually masturbating. He will then lie about this and call the other people perverts for trying to look at this dick. This type of person usually has a crease in their hand (much like somebody with down syndrome) and walks with a limp.
That guy threatened to tell on me for sluffing Algebra class, even though everybody knows he sucked off his best friend in the locker room last night. What a gongloid!