Sellun

Sellun is a term with no single, widely recognized meaning. In online discussions, games, and speculative fiction, it is used as a flexible label for a variety of concepts, ranging from a currency to a material to a place name. Because there is no standard definition, the interpretation of sellun varies by author and community.

Possible etymologies are informal; some writers suggest it originates in constructed languages, while others treat it as a neologism formed from familiar syllables intended to suggest exchange or energy. The lack of consensus contributes to its role as a neutral placeholder in worldbuilding.

In fictional contexts, sellun commonly denotes either a resource with energy-storage properties or a unit of value. In such settings, sellun may be described as a luminous mineral, a crystalline lattice, or a digital token. Its value may depend on purity, energy density, or a backstory tied to a civilization's mythology. Markets, treaties, and economies are often built around sellun as a central commodity.

Outside storytelling, sellun appears sporadically as a brand name or codeword in technology projects and indie games. There is no official standard measurement, mineralogy, or financial mechanism associated with sellun in real-world sources.

Because of its versatility, sellun is used in worldbuilding discussions as a practical placeholder for testing economic models or resource systems. The term remains ambiguous and is best treated as a fictional or hypothetical concept rather than an established term.