The terms "dimension" and "dimensionality" can have different meanings depending on the context in which they are used. In physics, dimensions often refer to spatial dimensions, such as length, width, and height. In this sense, the second dimension typically refers to a flat plane, like a sheet of paper, while the third dimension adds depth and allows for the representation of physical objects with volume.
If you are asking whether it is possible for a two-dimensional object, such as a flat plane, to exist within our three-dimensional world, the answer is yes. We often encounter two-dimensional representations of objects, like drawings or photographs, in our three-dimensional reality. These representations can accurately depict objects in a two-dimensional format.
However, if you are asking whether a true, independent two-dimensional object can exist within the three-dimensional world without any thickness or depth, it becomes a more abstract concept. In reality, all physical objects have some degree of thickness or depth, even if it is infinitesimally small. The laws of physics as we understand them do not allow for purely two-dimensional entities to exist independently in a three-dimensional universe.