Seclusion
Etymology
From Latin secludere, "to shut off, shut apart," from se-, "apart," plus claudere, "to close or shut" (the same root behind "close" and "cloister"). The literal image is of shutting a door between oneself and everyone else. English uses it for both the act of shutting away and the sheltered condition that results.
noun · /sih-KLOO-zhun/
The state of being shut away or kept apart from other people and the outside world.
What it names
A deliberate withdrawal behind some barrier — a place or arrangement that screens a person off, whether for privacy, safety, or retreat.
Example
The writer finished the novel in seclusion, renting a cabin with no phone signal for the entire winter.
Related idea
Solitude names how aloneness feels; seclusion names the physical shutting-off that produces it — you can be in seclusion and still feel crowded by your own thoughts.