fast·​ness | \ ˈfas(t)-nəs How to pronounce fastness (audio) \

Definition of fastness

1 : the quality or state of being fast: such as
a : the quality or state of being fixed
b : the quality or state of being swift
c : colorfast quality
d : resistance (as of an organism) to the action of a usually toxic substance
2a : a fortified or secure place
b : a remote and secluded place vacationed in their mountain fastness

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Examples of fastness in a Sentence

the amazing fastness with which the boy took his shower had us wondering if he'd used any water the guerillas retreated to their network of hidden fastnesses deep within the mountains

Recent Examples on the Web

Indeed, Lego can't reach its 2030 goal without solving ABS, a material that affords the company the attributes it so prizes: Durability, color fastness, strength, and clutch power, or how well two joined bricks stay together. Brian Barrett, WIRED, "Lego Builds a Sustainable Future, One Brick at a Time," 11 Mar. 2018 These enabled India to detect, and destroy by air, Pakistani troops entrenched in mountain fastnesses. Tunku Varadarajan, WSJ, "Modi and Netanyahu Begin a Beautiful Friendship," 5 July 2017 India kept the mostly Hindu rest of Jammu, the Vale itself and the desert-like fastness of Ladakh. The Economist, "Vale of darknessBuffeted by both India and Pakistan, it is the Kashmiris who suffer most," 20 July 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'fastness.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of fastness

before the 12th century, in the meaning defined at sense 1

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Time Traveler for fastness

The first known use of fastness was before the 12th century

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English Language Learners Definition of fastness

literary : a place that is difficult to get to or that can be easily defended if it is attacked


fast·​ness | \ ˈfas(t)-nəs How to pronounce fastness (audio) \

Medical Definition of fastness

: resistance (as of an organism) to the action of a usually toxic substance streptomycin fastness developed by a strain of tubercule bacillus

More from Merriam-Webster on fastness

Rhyming Dictionary: Words that rhyme with fastness

Thesaurus: All synonyms and antonyms for fastness

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