Fastness
Fastness , noun
[Anglo-Saxon fastnes, from fast fast. See Fast, a.]
1.
The state of being fast and firm; firmness; fixedness; security; faithfulness.
All... places of fastness [are] laid open.
2.
A fast place; a stronghold; a fortress or fort; a secure retreat; a castle; as, the enemy retired to their fastnesses in the mountains.
3.
Conciseness of style. [Obsolete] — Ascham
4.
The state of being fast or swift.