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
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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
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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
-
The questions continued when the Steelers rounded out their draft class with likely special teamers who have size (sixth-round, 6-5, 321-pound DT Gabriel Rubio) and speed (Oklahoma safety Robert Spears-Jennings ran the fastest 40 at the combine at his position) but need polish.—
Mike DeFabo,
New York Times,
27 Apr. 2026
-
Cops believe speed played a factor in the crash.—
Nicholas Williams,
New York Daily News,
26 Apr. 2026
Noun
-
Kidal had long served as a stronghold of the rebellion before being taken by Malian government forces and Russian mercenaries in 2023.—
Wilson Mcmakin,
Los Angeles Times,
26 Apr. 2026
-
After some 53 years, Antigone remains a no-frills stronghold where community organizers trade flyers near the entrance, and the inventory captures the perspectives of life in a vibrant border city.—
Kat Chen,
Condé Nast Traveler,
25 Apr. 2026
Noun
-
Members of the Atmos Rewards loyalty program can pack up to 12 bottles in a box or case weighing 50 pounds or less.—
Hali Smith,
Idaho Statesman,
29 Apr. 2026
-
Your laugh, your kindness, your wit, your strength, your loyalty, your passion, and your zest for life.—
Becca Longmire,
PEOPLE,
29 Apr. 2026
Noun
-
How the stars in a binary system orbit one another — their orbital period and velocity — depends on the masses of the two stars.—
Keith Cooper,
Space.com,
28 Apr. 2026
-
But Lamar’s velocity reflects his ambition.—
New York Times,
New York Times,
28 Apr. 2026
Noun
-
For security officials, building a fortress is relatively easy.—
Juliette Kayyem,
The Atlantic,
27 Apr. 2026
-
No such fortress for the federal and state officials who face growing number of threats in communities across the country.—
CBS News,
CBS News,
26 Apr. 2026
Noun
-
Winston’s sports allegiances have changed, too.—
Julie Belcove,
Robb Report,
25 Apr. 2026
-
Brian was obsessed with being the Rolling Stones’ leader but had grown moody ever since Keith’s allegiance shifted to Mick.—
Literary Hub,
Literary Hub,
21 Apr. 2026
Noun
-
For more than a hundred years, the place has functioned as a crucial cultural bastion, hosting speakers like James Baldwin, Gwendolyn Brooks, and Allen Ginsberg.—
Brittany Allen,
Literary Hub,
21 Apr. 2026
-
But that is not so much true in Florida, where Cubans remain a bastion of GOP support.—
Natalia Jaramillo,
The Orlando Sentinel,
17 Apr. 2026
Noun
-
The team held a pre-game ceremony at Truist Park to celebrate Snitker, 70, for his illustrious career and dedication to the franchise.—
Gabriel Burns,
AJC.com,
26 Apr. 2026
-
What stood out most was the crew’s dedication and enthusiasm, along with the intimacy of the experience; the ship is designed for just 100 guests.—
David Morris,
Travel + Leisure,
26 Apr. 2026
Cite this Entry
“Fastness.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/fastness. Accessed 2 May. 2026.
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