outsides

Outsides is the plural form of outside when used as a noun. It generally refers to the exterior parts or surfaces of objects, or to exterior regions of a place. The term contrasts with inside, which denotes interiors or inner parts. While outside is commonly used as both adjective and noun, outsides is used mainly when multiple exterior parts or areas are involved.

In architecture and construction, outsides describe the external facades, cladding, or outer walls of buildings. In geography and urban planning, the outsides of an area refer to its exterior boundaries and surrounding spaces. In everyday language, people may speak of the outsides of objects, such as the outsides of a box or a fruit, though more precise terms like exterior surface or outer layer are common. The word is typically plural when referring to several separate exterior elements rather than to a single item.

In other senses, outsides is rarely used to denote people who are not part of a group; in such cases outsiders is the standard term. Etymologically, outsides derives from outside, with the plural form functioning as a noun indicating external parts or areas. Related terms include exterior, exteriority, facade, and outer surface.