Meaning of the word fastness in English

What does fastness mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

fastness

US /ˈfæst.nəs/
UK /ˈfɑːst.nəs/

Noun

1.

the quality of being firmly fixed or securely attached

Example:
The fastness of the knot ensured the rope would not slip.
We tested the color fastness of the fabric.
2.

a secure and secluded place, especially a fortress or stronghold

Example:
The ancient castle served as a formidable fastness against invaders.
They retreated to their mountain fastness to plan their next move.