What is the opposite word for exterior?

The opposite word for exterior is interior, which means inside, inner part, inner space, or inner nature. Exterior means outside, outer part, outer surface, or outward appearance, so interior is direct antonym meaning inside part. For example, exterior of house is outside walls, yard, and facade, interior of house is inside rooms, walls, and living spaces. Exterior paint is for outside, interior paint is for inside. Other opposites depending on context include inside, inner, internal, inward, inner side, and indoors. For adjective exterior meaning outer, opposite is inner, internal, inside, or inward. For noun exterior meaning outside space, opposite is inside, interior, inner area, or indoors. In personal context, exterior meaning outward appearance, opposite is interior meaning inner character. So main antonym is interior, which is used in architecture, design, and general language as opposite pair, as in interior and exterior design, interior and exterior walls, interior and exterior spaces. If you say exterior, opposite is interior, and if you say outside, opposite is inside.