Addy is usually a nickname for the common girl name Addison. Addy is a great friend and will always be there for you. They are often shy but around her friends she will talk a lot. There is always at least one guy who will have a crush on her. Addy's are also a great girlfriend to have. They are usually very good looking. Once people get to know her they will never regret becoming friends with her.
"Hey who is that girl? She never talks!"
"That's Addy I'm her best friend and she never stops talking!"