- the quality or condition of being fast
- a secure place; stronghold
Origin of fastnessMiddle English fastnesse from Old English fæstnes: see fast and -ness
- The condition or quality of being fast, especially:a. Firmness; security.b. Rapidity; swiftness.
- The quality or condition of color retention; colorfastness.
- a. A secure or fortified place; a stronghold.b. A remote, secret place.