The Chinese word 户外 (hùwài), meaning "outdoors" or "open air", is a compound noun formed through the straightforward combination of two meaningful characters: 户 (hù), which originally means "door" or "household", and 外 (wài), which means "outside" or "external". Together, they create a literal spatial concept of "outside the door/house", which semantically extends to refer broadly to the realm of outdoor activities and environments, such as hiking or camping, effectively capturing the idea of the world beyond the confines of indoor spaces.