Somnambulation is the act of walking while asleep. It is also known as sleepwalking. There are many synonyms for the word somnambulation, including noctambulation, which means walking at night. Hypnambulation is another synonym, which refers to the condition of walking while in a trance-like state. Another similar term is automatism, which describes any unconscious and involuntary movement. Parasomnia and somnolence are words that are also used to describe sleep-related behavior. Regardless of the term used, sleepwalking can be quite dangerous if the person is not properly supervised and cared for to avoid harm.