1
as in speed
a high rate of movement or performance
the amazing fastness with which the boy took his shower had us wondering if he'd used any water
Synonyms & Similar Words
Relevance
Antonyms & Near Antonyms
2
as in stronghold
a structure or place from which one can resist attack
the guerillas retreated to their network of hidden fastnesses deep within the mountains
Synonyms & Similar Words
3
as in loyalty
adherence to something to which one is bound by a pledge or duty
his uncompromising fastness to the cause of freedom was beyond question
Synonyms & Similar Words
Antonyms & Near Antonyms
Example Sentences
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Recent Examples of fastness
Editors and contributors compare dozens of sets and look for qualities such as softness, durability, breathability, color fastness, and how well the linens launder and withstand wear.
—
Yelena Moroz Alpert, Architectural Digest, 20 Jan. 2026
Li said the color builds the familiar ring-dye, white-core look designers expect, then fades predictably in laundry while maintaining high light fastness (Grade 4–5) and strong anti-yellowing.
—Angela Velasquez, Sourcing Journal, 11 Nov. 2025
Like the pressing, the hard work mentality and fastness of transition for example.
—Andy Jones, New York Times, 29 May 2025
The Neutral Ground had cowboys (or Cow Boys), Indians, cavalry attacks and rescues, and secret woodland fastnesses known only to the canniest frontiersman.
—Ian Frazier, The New Yorker, 15 July 2024
Yelena Moroz Alpert, Architectural Digest, 20 Jan. 2026
Li said the color builds the familiar ring-dye, white-core look designers expect, then fades predictably in laundry while maintaining high light fastness (Grade 4–5) and strong anti-yellowing.
—Angela Velasquez, Sourcing Journal, 11 Nov. 2025
Like the pressing, the hard work mentality and fastness of transition for example.
—Andy Jones, New York Times, 29 May 2025
The Neutral Ground had cowboys (or Cow Boys), Indians, cavalry attacks and rescues, and secret woodland fastnesses known only to the canniest frontiersman.
—Ian Frazier, The New Yorker, 15 July 2024
Recent Examples of Synonyms for fastness
Noun
-
Winter Olympic athletes, particularly those who compete in events that involve flying down a mountain or icy track at breakneck speeds, are not exactly known for self-preservation instincts.—
Lindsay Schnell,
New York Times,
9 Feb. 2026
-
With China’s lunar program picking up speed, the pressure is on for the US to reclaim the lunar surface — a destination that has remained untouched by humans for over 50 years.—
Mrigakshi Dixit,
Interesting Engineering,
9 Feb. 2026
Noun
-
Still, even in states where gambling has been legal — the strongholds of DraftKings and FanDuel — there have been signs of weakness.—
Peyton Forte,
Fortune,
8 Feb. 2026
-
Texas Senate District 9 has historically been a red stronghold, but that doesn’t appear to be the case anymore after Rehmet’s upset victory.—
David Zimmermann,
The Washington Examiner,
8 Feb. 2026
Noun
-
Accountability builds safety and loyalty; shifting blame never works for long.—
Magi Helena,
Dallas Morning News,
11 Feb. 2026
-
The Cineplex chief said data from the company’s Scene loyalty program helps target the right theaters and showtimes to reach diverse and multicultural audiences across Canada.—
Etan Vlessing,
HollywoodReporter,
11 Feb. 2026
Noun
-
But none of these innovations used digital technology to increase velocity, because of power constraints.—
Chloe Veltman,
NPR,
10 Feb. 2026
-
This refers to the total change in velocity and direction that a spacecraft is capable of achieving over time.—
Chris Young,
Interesting Engineering,
10 Feb. 2026
Noun
-
Those interested in the history of the fortress can learn more in the six different on-site museums.—
Lydia Mansel,
Travel + Leisure,
4 Feb. 2026
-
At the end of a winding valley road deep in the Purcell Mountains, Panorama Mountain Resort feels like a secret fortress of skiing.—
Brent Rose,
Condé Nast Traveler,
1 Feb. 2026
Noun
-
Academy-award winner and Alabama native Octavia Spencer makes no bones about where her allegiance lies on the football field.—
Rebecca Angel Baer,
Southern Living,
6 Feb. 2026
-
Officials like Raffensperger and Carr put their duty to the people of their state before their allegiance to their party.—
Barbara McQuade,
Twin Cities,
6 Feb. 2026
Noun
-
But even on state TV -- long a bastion of pro-government propaganda and ideological control -- cracks have started to appear.—
EGINA GARCIA CANO,
Arkansas Online,
8 Feb. 2026
-
True to its founding fight over censorship and book banning, the institution remains a bastion dedicated to the transformative power of the book.—
Gioia Woods,
Literary Hub,
6 Feb. 2026
Noun
-
The week will highlight the show’s dedication to celebrating women who inspire change, break barriers and uplift one another.—
Denise Petski,
Deadline,
9 Feb. 2026
-
Dear Academy members, Thank you for your dedication and participation this Oscars season.—
Scott Feinberg,
HollywoodReporter,
9 Feb. 2026
Cite this Entry
“Fastness.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/fastness. Accessed 14 Feb. 2026.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
