Final answer:
The word commonly associated with outer space in science fiction is 'extraterrestrial'. It signifies anything outside Earth's atmosphere, often related to alien life and is frequently explored in sci-fi media.
Step-by-step explanation:
When watching science fiction movies or reading sci-fi books, the word that is commonly associated with outer space is extraterrestrial. This term refers to anything of or from outside the earth or its atmosphere and is often used to describe life that may exist on other planets or moons. Science fiction often explores concepts like contact with extraterrestrial beings, the possibility of life on other planets, and space travel. For instance, the film Interstellar deals with space travel near a black hole, while the Starship Enterprise from Star Trek is known for discovering new planets. Writers draw inspiration from the latest scientific findings, such as exoplanet discoveries, to craft narratives that reach beyond our current technological capabilities and imagine what contact with extraterrestrial life might be like.