Flat feet or fallen arches are a common foot condition where the arches of the feet touch the ground when standing. There are several synonyms that can be used to describe flat feet. One such term is pes planus, which is a medical terminology used to describe flat feet. Another synonym is pronation, which indicates excessive inward rolling of the feet. Some other synonyms for flat feet include collapsed arches, low arches, dropped arches, and fallen arches. These terms all refer to the same condition and are used interchangeably by health care professionals. Flat feet can cause discomfort and pain, and individuals who experience these symptoms are advised to seek medical attention.