fastness

noun

fast·​ness ˈfas(t)-nəs How to pronounce fastness (audio)
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
2
a
: a fortified or secure place
b
: a remote and secluded place
vacationed in their mountain fastness

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 Branagh returns as Hercule Poirot, who has retired to a Venetian fastness. Anthony Lane, The New Yorker, 15 Sep. 2023 When using natural dyes, there tend to be issues with color fastness and shade consistency. Esha Chhabra, Forbes, 22 Feb. 2023 Unlike the Brahui the Burusho are very isolated in the mountainous fastness of Baltistan in northern Pakistan. Razib Khan, Discover Magazine, 20 Dec. 2010 Even though the Speedo Fastskin FSII material didn't show any signs of inherent fastness (and seemed to actually increase drag, compared to when it was turned smooth-side-out), that doesn't discount the Speedo swimsuit as a whole. Elizabeth Preston, Discover Magazine, 14 Feb. 2012 Test for color fastness before stitching onto bedding and washing. Sonja Carmon, Better Homes & Gardens, 14 Apr. 2021 Given their advance into Labour’s working-class fastness, the Tories’ worst nightmare is not a Labour Party that returns to the old centre as defined by Tony Blair. The Economist, 13 Dec. 2019 The other tragedy occurred far from the public eye, in one of the last remote fastnesses of the world. Ipsita Chakravarty, Quartz India, 10 June 2019 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, 11 Mar. 2018

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'fastness.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

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

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

Dictionary Entries Near fastness

Cite this Entry

“Fastness.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/fastness. Accessed 28 Mar. 2024.

Kids Definition

fastness

noun
fast·​ness ˈfas(t)-nəs How to pronounce fastness (audio)
1
: the quality or state of being fast
2
: a fortified or secure place

Medical Definition

fastness

noun
fast·​ness ˈfas(t)-nəs How to pronounce fastness (audio)
: resistance (as of an organism) to the action of a usually toxic substance
streptomycin fastness developed by a strain of tubercule bacillus
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