| Definition: An independent continuant that is a lower dimensional part of a spatial entity, normally a closed two-dimensional surface. Boundaries are those privileged parts of objects that exist at exactly the point where the object is separated off from the rest of the existing entities in the world. |
| Examples: the surface of the skin, the surface of the earth, the surface of the interior of the stomach, the outer surface of a cell or cell wall |
| •owl:Thing |
| •entity |
| •continuant |
| •independent_continuant |
| •object_boundary |