Used future
Also said as Lived-in world, Dirty sci-fi, Wear and tear
A world whose things are old, dented and repaired, so they seem to have been in use for years. George Lucas used the phrase about Star Wars in 1977, and it applies to any setting, not only the future.
New things look like props. Wear is evidence of people: where they walk, what breaks often, what no one bothered fixing. It suggests a past without saying a word.
Say it
“Make this ship feel lived in. Wear the floor where the crew walk from bunks to galley, tape the kettle's handle, and leave the panel that always breaks with its screws missing.”
Where you’ve seen it
Alien: Isolation set itself the rule of building nothing that could not have been built on the set of the 1979 film. Its chunky CRT monitors and worn corridors feel like a real ship owned by a mean company.
Not to be confused with post-apocalypse
A post-apocalypse is a world that has ended. A used future is a world still at work, with things simply getting old in use.