This study deals with formlessness designs that indicate a variety of related shapes between the human body and clothes depending on the 2D shape of fabric rather than a cubic and clear shape of fabric proportional to the human body. There have been formlessness fashion designs since the 1980s; however, there has been no attempts to define the concept of formlessness fashion designs. This study focuses on how formlessness clothing was named for clothes with no specific shape due to recognizing the body as a flat surface as referred in various prior studies and how a formlessness design is expressed. This study reviews formlessness designs from the viewpoint of eastern concepts as well as from the viewpoint of ancient Greek clothes to understand how eastern and western designers approached formlessness designs. We also simultaneously utilize a literature research and a case study of actual work. The scope of the research focuses on the case of female clothing starting from the 1980s when the formlessness trend first appeared.