I think it is slang. I have heard this word in songs like Sean Kingston- Take You There and Justin Bieber- One Time. As you can see they are both written by boys. In the song Take You There by: Sean Kingston they said this: "Shorty I can take you there." The other song One Time by: Justin Bieber they said this in the song: "Shorty like that, she's got everything I need." They are both talking about a girl.