A person, who acts in a special way and is not afraid to do so. Usually a small, cute, person who is very happy and can make you laugh whenever they want to. Also some one who is very fun to be around and acts in the silliest way possible.
Why are you so cute, you sillybilly.
by Adafusio February 12, 2009
An proclaimation of victory used by someone at least 25 years older than their opponent. It is such a bad insult, that only the older (or should I say wiser? Maybe not...) can use it and not look stupid. It basically means that their opponent is too immature to be treated to a real insult.
Silly Billy, don't fuck wit dees old ass niggaz.
by Gumba Gumba March 05, 2004
N. Ghetto slang used by black people, rappers, and porn-stars used to replace the words 'fucking retard'. More effectively used when the person being referred to is named Bill or William.
Wow Em, you should really put your clothes back on, we are at church! You are acting like a Silly Billy.
by Chuck Justin. January 23, 2010