look up any word, like bye felicia:
 
1.
a mountain goat with down syndorome
He is a silly billy
by Nick April 30, 2003
143 75
 
2.
Although strictly speaking a derogatory term as defined above, it can (and often is) also used affectionately.
A: Where is Billy Littleknife?
B: I dunno. Stop asking such questions and come here.. You Silly Billy, you !

snogging ensues....
by FireWalls2000 May 13, 2010
86 26
 
3.
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
23 3
 
4.
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
48 73
 
5.
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
27 60
 
6.
possibly the coolest nickname 2 have scinec Yo momma
" Ur silly, ur billy OKAY!
by Sexiness April 12, 2005
29 67