A "jacket dress" refers to a type of outfit where a dress is worn with a matching or coordinating jacket or blazer. It adds a layer of style and can make the look more put-together or formal. Full definition
Even though the look is overall pretty basic, I think the leather jacket dresses it up a bit to make it a little more put together. (seekingsunshine.com)
Another trendy item of fall 2015 like jacket dress comes handy when you want to create sophisticated look. (jenniferkaya.com)