Definition: The word "archigastrula" refers to a type of cleft palate, a defect in the development of the upper jaw bones. It can occur due to an abnormal growth or change in the structure of the jaw bone itself or through other conditions that affect bone development. This condition is called "cleft palate." The name comes from the Greek word "archi," meaning "on" and "gastrula," which refers to the opening part of the mouth, similar to how an arch is formed by opening a door or window with its top open.