fort

Etymology

From Middle English fort, from Middle French fort (“strong”) (adjective use is from Old French). Doublet of fortis and forte.

noun

1. A fortified defensive structure stationed with troops.
2. Any permanent army post.
3. (historical) An outlying trading-station, as in British North America.
4. A structure improvised from furniture, bedding, etc., for playing games.
   The kids built a fort out of chairs and pillows.

verb

1. To create a fort, fortifications, a strong point, or a redoubt.