sillybilly

   A gentle term of address, usually far more intimate than insulting, spoken to a child or to a lovepartner. It is used to a child in Room at the Top, by John Braine. Partridge says in his Dictionary of Historical Slang that a sillybilly was originally, in the mid-nineteenth century, the juvenile butt of a circus clown. The second element was no doubt used for rhyming convenience.