outside
n. countable A2 Elementary Oxford US //ˈaʊtˈsaɪd// out·side
n. the part of something that faces away from the center. It is the surface or the area that is not on the inner part.
n. the external surface or part of an object; the area beyond the boundaries of a specific space.
The outside of the house is painted white.
The outside of the fruit is rough and brown, but the inside is sweet and soft.
Architects often focus on how the outside of a building interacts with the surrounding landscape to create a sense of harmony between the structure and nature.
From out + side.
Usage
Often used with the definite article 'the' when referring to a specific surface or boundary.