slack·​en | \ˈsla-kən \
slackened; slackening\ ˈsla-​kᵊn-​iŋ \

Definition of slacken 

transitive verb

1 : to make less active : slow up slacken speed at a crossing

2 : to make slack (as by lessening tension or firmness) slacken sail

intransitive verb

1 : to become slack or slow or negligent : slow down

2 : to become less active : slack

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Synonyms & Antonyms for slacken


brake, decelerate, retard, slow


accelerate, hasten, hurry, quicken, rush, speed (up), step up

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Choose the Right Synonym for slacken

delay, retard, slow, slacken, detain mean to cause to be late or behind in movement or progress. delay implies a holding back, usually by interference, from completion or arrival. bad weather delayed our arrival retard suggests reduction of speed without actual stopping. language barriers retarded their progress slow and slacken also imply a reduction of speed, slow often suggesting deliberate intention medication slowed the patient's heart rate , slacken an easing up or relaxing of power or effort. on hot days runners slacken their pace detain implies a holding back beyond a reasonable or appointed time. unexpected business had detained her

Examples of slacken in a Sentence

Sales show no sign of slackening. As he began to relax, his grip on the steering wheel slackened. The captain ordered us to slacken the sails.
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Recent Examples on the Web

Confidence: High Tomorrow night: Winds slacken as high pressure overtakes the region. Brian Jackson, Washington Post, "D.C.-area forecast: A soggy, cold Super Bowl Sunday with patchy ice," 4 Feb. 2018 Once demand for crab feasts slackens, picking houses become important buyers of any of those undersized crustaceans. Scott Dance,, "After July Fourth crab feasts, an uncertain season for Maryland seafood industry," 6 July 2018 Retail auto sales slackened last month, and unsold cars have started accumulating at dealerships. Keith Bradsher, New York Times, "As China Curbs Borrowing, Growth Shows Signs of Faltering," 14 June 2018 On top of that, generally dominant sunshine and slackening winds. A. Camden Walker, Washington Post, "D.C.-area forecast: Some windy chill left today, but temperatures slowly warm and breezes wane this weekend," 20 Apr. 2018 Since then, critics claim, regulatory oversight has slackened. The Economist, "Australia’s biggest river is running dry, despite plans to save it," 19 May 2018 Labor militancy never slackened, but only positive intervention from the American state permanently changed the balance of power. David Sessions, The New Republic, "The Meaning of American Factories," 2 Apr. 2018 Eventually your skin will slacken and your eyelids will fall to half-mast. Ali Wentworth, Harper's BAZAAR, "Who Me? Irrelevant? An Essay On Aging," 29 Mar. 2018 Any slackening in the intensity of the snowfall would allow warming, and with temperatures near or even above freezing, the snow could up mixing with or even changing to rain. Ian Livingston, Washington Post, "Winter storm likely Monday night into Tuesday; snow accumulation odds are growing for parts of the D.C. region," 17 Mar. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'slacken.' 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 slacken

14th century, in the meaning defined at transitive sense 1

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Statistics for slacken

Last Updated

29 Oct 2018

Look-up Popularity

Time Traveler for slacken

The first known use of slacken was in the 14th century

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More Definitions for slacken



English Language Learners Definition of slacken

: to become slower or less active : to slow down

: to make (something) slower or less active

: to become less tight or to make (something) less tight


slack·​en | \ˈsla-kən \
slackened; slackening

Kids Definition of slacken

1 : to make slower or less energetic The wind slackened.

2 : to make less tight or firm She slackened the reins.

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Comments on slacken

What made you want to look up slacken? Please tell us where you read or heard it (including the quote, if possible).


something that serves to warn or remind

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