FASTNESS Synonyms: 108 Similar and Opposite Words

fastness

noun

ˈfas(t)-nəs

Definition of fastness

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

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

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 The redyed fabrics showed uniform color uptake and washing and rubbing fastness comparable to the reference fabric, according to the study. — Alexandra Harrell, Footwear News, 26 Aug. 2026 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

Recent Examples of Synonyms for fastness

Noun

The release did not specify the vessel’s operating range, charging time, service speed, or construction schedule.

— Atharva Gosavi, Interesting Engineering, 23 Oct. 2026
Motorists are also advised to maintain a safe speed in work zones.

— Sean Krofssik, Hartford Courant, 22 Oct. 2026

Definition of speed

Noun

The Republican strongholds of the Texas Panhandle and deep East Texas could also help reveal the statewide political picture.

— Marvin Hurst, CBS News, 20 Oct. 2026
Alberta is considered a conservative stronghold, but the Liberal Party has led the country for over a decade.

— Chantelle Lee, Time, 20 Oct. 2026

Definition of stronghold

Noun

My business experience has shown me that clients feel more loyalty and comfort with a company willing to work through difficult periods with them.

— Mark Berookim, Forbes.com, 26 Oct. 2026
In the Buendías’ legacy of love and betrayal, loyalty and idealism, there was domestic and political violence, but there was also ice in the middle of the jungle and a sickness that put the whole town to sleep and girls that became witches.

— Literary Hub, Literary Hub, 26 Oct. 2026

Definition of loyalty

Noun

In an era of baseball where launch angle and exit velocity are emphasized, home runs are prioritized and striking out has become far too acceptable, Simpson plays a different style.

— ABC News, ABC News, 22 Oct. 2026
In addition, since all this debris is moving at orbital velocity, a fleck of paint traveling in the opposite direction to an operational satellite can hit it at a speed in excess of Mach 47.

— New Atlas, New Atlas, 22 Oct. 2026

Definition of velocity

Noun

According to the brand, these mushrooms were actually found growing in the cellar of the nearby Wilhelmsburg fortress, so the team decided to use them to add some umami flavor to the gin.

— Jonah Flicker, Robb Report, 21 Oct. 2026
The Roman city of Cologne and a legionary fortress in Bonn were also nearby — raising the possibility of a military connection.

— Andrea Margolis, FOXNews.com, 11 Oct. 2026

Definition of fortress

Noun

Although some Republicans have derided the state Supreme Court as being a bastion of liberal activists, five of the Supreme Court’s seven judges were appointed by Republican governors.

— Jeremy Kohler, ProPublica, 15 Oct. 2026
And with Democrats in hegemonic control of Sacramento, the state had become the country’s preeminent bastion of liberal values and policies.

— Los Angeles Times, Los Angeles Times, 14 Oct. 2026

Definition of bastion

Browse Nearby Words

fasting

fastness

fasts

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Style

“Fastness.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/fastness. Accessed 28 Oct. 2026.

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Synonyms of fastness

noun

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