Fast"ness, n. [AS.
fæstnes, fr. fæst fast. See Fast,
a.] 1. The state of being fast
and firm; firmness; fixedness; security; faithfulness.
All . . . places of fastness [are] laid
open.
Sir J. Davies.
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. [Obs.]
Ascham.
4. The state of being fast or
swift.