The combining form ambul- refers to walking, movement, or mobility. It appears in physical therapy, rehabilitation, and functional status documentation. The prefix “ambul-” originates from the Latin word “ambulare,” meaning “to walk, to take steps, or to go around,” and words containing this prefix typically relate to movement or transportation. This root is present in English words such as “amble,” “ambulance,” and “perambulator,” with its sense broadening in French to encompass anything related to general movement, leading to words like “ambulant” (itinerant/mobile) and “somnambule” (sleepwalker).