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

In reality, both objects orbit the star in the same direction, just at different, changing speeds.

— Phil Plait, Scientific American, 16 Oct. 2026
Power is routed to the rear wheels through a new six-speed manual gearbox.

— Bradley Iger, Robb Report, 16 Oct. 2026

Definition of speed

Noun

Arizona stands out as the lone swing state among the president’s recent stops, though the airport rally will be in an area of the state known as a Republican stronghold.

— Will Weissert, Los Angeles Times, 14 Oct. 2026
Arizona stands out as the lone swing state among the president's recent stops, though the airport rally will be in an area of the state known as a Republican stronghold.

— ABC News, ABC News, 14 Oct. 2026

Definition of stronghold

Noun

Still, Saudi Arabia has viewed attendance at the event, and general support for the Gulf during turbulent times, as a loyalty test for global business leaders.

— Liz Hoffman, semafor.com, 19 Oct. 2026
The Maryland and New Jersey laws focus on groceries, with exceptions for certain loyalty discounts and other promotional offers.

— Arkansas Online, Arkansas Online, 19 Oct. 2026

Definition of loyalty

Noun

Businesses that rediscover its values will gain what their velocity-chasing competitors cannot buy, borrow, or automate.

— Matt Alt, Fortune, 18 Oct. 2026
The Patriot munition at a critical low is the Patriot Advanced Capability-3, or PAC-3, a high-velocity surface-to-air interceptor designed to destroy incoming tactical ballistic missiles and cruise missiles by ramming into them.

— James LaPorta, CBS News, 15 Oct. 2026

Definition of velocity

Noun

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
Supporters of the movement gathered in New Delhi Saturday despite the capital turning into a fortress to keep out protesters.

— Ayushi Shah, CNN Money, 10 Oct. 2026

Definition of fortress

Noun

Yet the political alternatives that once dominated the region have lost their capacity to command popular allegiance.

— Mansoor Moaddel, Foreign Affairs, 15 Oct. 2026
Countries including Nauru, Honduras and Nicaragua have switched allegiances from Taiwan to Beijing in recent years.

— ABC News, ABC News, 12 Oct. 2026

Definition of allegiance

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 21 Oct. 2026.

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Synonyms of fastness

noun

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