A fortified place, especially a large, permanent military stronghold that often includes a town. (noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "fortress" in a sentence
"By far the most remarkable sight in the fortress is the late works performed by that little enterprizing adventurous animal calld Man."
"“Yes, the Forerunners built this place, what they called a fortress world, in order to —”"
"This fortress is as ancient as the town, said to have been built about the middle of the twelfth century, and is situated on an elevation at the foot of which flows the Moskva, but there is nothing remarkable in the style excepting its antiquity."