"Chattle" is actually spelled Chattel and comes from a Middle English word meaning "property." It is commonly used to refer to degraded or enslaved people; those seen as property. In some areas, it has a racist connotation. If you are going to be a bigot, at least learn how to spell your slurs.
In the early days of the United States, human beings were often traded like chattel (misspelled as chattle).