worldbuilding

noun

1. (uncountable)The conception and description of a fictional world, often as the setting of a work of fiction, particularly in speculative fiction.

   “The purpose of worldbuilding isn't just to do a cool exercise, but to give a sense of place — and all of your thought experiments absolutely have to result in something vivid and alive.”

   “High fantasy of the George RR Martin kind hinges on world-building. When there really is a whole world to build, and not just a historical period or a particular country, world-building does not take a few paragraphs in a short story; it takes chapters.”

   “A sequel of this magnitude has the ability to reach higher, though, with more creative worldbuilding balancing out the dime-a-dozen pop culture references and cheap gags.”

2. (obsolete, uncountable)Scientific research into the creation of the Earth and its geological features.
3. (obsolete, uncountable)The world of imagination of novelists, poets, etc.