fastness

noun fast·ness \ ˈfas(t)-nəs \
Updated on: 18 Mar 2018

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
2 a : a fortified or secure place
b : a remote and secluded place
  • vacationed in their mountain fastness

Examples of fastness in a Sentence

  1. the amazing fastness with which the boy took his shower had us wondering if he'd used any water

  2. the guerillas retreated to their network of hidden fastnesses deep within the mountains

Recent Examples of fastness from the Web

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.

First Known Use of fastness

before 12th century

in the meaning defined at sense 1

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FASTNESS Defined for English Language Learners

fastness

Definition of fastness for English Language Learners

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


Medical Dictionary

fastness

noun fast·ness \ ˈfas(t)-nəs \

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


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