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
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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
-
New York City imposed a speed limit of 15 mph on all electric bikes in October, and Florida lawmakers recently sent the governor a bill limiting e-bike speeds to 10 mph within 50 feet of pedestrians.—
Sarah Raza,
Chicago Tribune,
30 Mar. 2026
-
Curves present a natural speed deterrent.—
Charlotte Observer,
Charlotte Observer,
30 Mar. 2026
Noun
-
He was killed in southern Lebanon, a stronghold of the militant group Hezbollah, as Israel expands an invasion there.—
ABC News,
ABC News,
29 Mar. 2026
-
Journalists heard several explosions from the direction of the Hezbollah stronghold, which Israel has repeatedly struck since war began.—
CBS News,
CBS News,
28 Mar. 2026
Noun
-
That pack loyalty appeared to be what kept them united through their harrowing escape and long walk home.—
Hanna Wickes,
Miami Herald,
25 Mar. 2026
-
Common projects focus on strengthening profitable growth initiatives such as improving loyalty programs, responding to competitive threats, or identifying strategies to lift comparable store sales.—
Malana VanTyler,
USA Today,
25 Mar. 2026
Noun
-
His fastball, meanwhile, enjoyed an uptick in velocity and yielded more swing and miss, characteristics that lacked for most of the pitcher’s spring and throughout a 2025 season that was delayed by a lat injury.—
Gary Phillips,
New York Daily News,
25 Mar. 2026
-
His 95-96 mph velocity seemed just fine.—
Evan Grant,
Dallas Morning News,
24 Mar. 2026
Noun
-
When a crew member is found dead and another goes missing, military investigators board the floating fortress, with its 2,000-strong crew and nuclear payload, to hunt for the truth before the murder becomes a global security crisis.—
Scott Roxborough,
HollywoodReporter,
24 Mar. 2026
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One focus of Russian attacks has been the town of Lyman in Donetsk, at the edge of what’s known as Ukraine’s fortress belt in the region, and a key strongpoint guarding the larger city of Sloviansk.—
Tim Lister,
CNN Money,
22 Mar. 2026
Noun
-
The day started on the CPAC main stage with the pledge of allegiance, the national anthem and Arizona pastor Joshua Navarrete’s prayer asking for blessings for the president and Israel.—
Eleanor Dearman,
Fort Worth Star-Telegram,
26 Mar. 2026
-
Virunga's forests are also believed to have been used as a hideout by fighters from the ADF militia, which has pledged allegiance to the Islamic State jihadist group.—
CBS News,
CBS News,
26 Mar. 2026
Noun
-
Military engineers resorted to building lower, thicker ramparts, backed by earth, and sought to eliminate blind spots by building angular bastions — the aforementioned extrusions.—
Big Think,
Big Think,
27 Mar. 2026
-
Malls in the Gulf have been a bastion of normalcy amid the instability, although footfall is substantially down on usual levels.—
Kelsey Warner,
semafor.com,
26 Mar. 2026
Noun
-
Mike Alexander, a frequent flier traveling to Orlando before heading to Indianapolis to watch the Michigan men's basketball team compete in the Final Four, praised the dedication of TSA officers.—
Hannah McIlree,
CBS News,
30 Mar. 2026
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The dedication event honored the Rancho Mission Viejo Rodeo’s long-standing support of The Shea Center and other south Orange County nonprofits through the RMV Rodeo proceeds.—
Magda Liszewska,
Oc Register,
30 Mar. 2026
Cite this Entry
“Fastness.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/fastness. Accessed 31 Mar. 2026.
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