In Hindu literature, the term "loka" does not have a fixed and universally agreed-upon definition. Its meaning can vary depending on the context and the specific texts being referred to. However, generally speaking, a "loka" is often interpreted as a realm or a world.
In some texts, "loka" is used to describe a planet or a celestial body. For example, there are references to different "lokas" such as Bhu-loka (Earth), Swarga-loka (heaven), Patala-loka (underworld), and so on. These "lokas" are considered distinct realms or worlds within the cosmology of Hindu mythology.
On the other hand, in certain philosophical and cosmological texts, "loka" can refer to a larger cosmic system or a universe. It is described as a multidimensional realm that encompasses various planes of existence, realms, and dimensions. These texts often present a complex cosmology with multiple "lokas" or worlds, interconnected through different levels of reality.
Therefore, while "loka" can refer to a planet in some contexts, it can also represent a solar system or even a universe in other contexts. It's important to consider the specific text and the interpretation within Hindu mythology or philosophy to determine the exact meaning of "loka" in a given context.