fastness
UK: ˈfɑːstnəs | US: ˈfæstnəs
n. the quality or state of being firm, fixed, or resistant to change
n. a secure or fortified place; a stronghold
n. (archaic) swiftness; speed
The word "fastness" combines the Old English root "fæst," meaning "firm" or "swift," with the suffix "-ness," which forms abstract nouns indicating a state or condition. Originally, "fast" in Old English (fæst) could mean both "firmly fixed" (e.g., "hold fast") and "rapid" (e.g., "run fast"). Over time, "fastness" evolved to emphasize the idea of firmness or security (e.g., a "stronghold"), while the speed-related meaning became archaic. The suffix "-ness" is a productive morpheme in English, derived from Proto-Germanic *-nassu, used to create nouns from adjectives.
The castle's fastness made it nearly impervious to attack.
The fastness of the dye ensured the fabric remained vibrant after many washes.
(Archaic) The horse's fastness amazed the spectators at the race.
The mountain fastness provided refuge for the rebels during the war.
Her fastness in adhering to principles earned her great respect.