The term "fallen arch" is commonly used to describe a condition called flat feet, which refers to the flattening of the arch on the inside of the foot. There are several synonyms for this condition, including pes planus, flatfoot, and collapsed arches. Other terms that may be used to describe fallen arches include fallen or dropped arches, overpronation, and hyperpronation. In some cases, people may refer to fallen arches as fallen arch syndrome or flat foot disorder. These terms all describe the same condition, which can lead to discomfort, pain, and difficulty with certain activities.