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Synonyms

slacken

American  
[slak-uhn] / ˈslæk ən /

verb (used with or without object)

  1. to make or become less active, vigorous, intense, etc.

    Synonyms:
    abate, slack, loosen, relax
  2. to make or become looser or less taut.

    Synonyms:
    abate, slack, loosen, relax
    Antonyms:
    tense, tighten

slacken British  
/ ˈslækən /

verb

  1. to make or become looser

  2. to make or become slower, less intense, etc

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

Etymology

Origin of slacken

First recorded in 1570–80; slack 1 + -en 1

Explanation

To slacken is to loosen the tension on or tightness of something. If you slacken the clothesline any more, the clothes will be on the ground next time you hang out the wash. Slacken, in the "to loosen" sense, can also be used figuratively. Because you have been so responsible, we're going to slacken the rules about curfew on non-school nights and let you stay out an hour later. Slacken also means to slow down or make less active. If you are in a sprint race, you won't want to slacken your pace until after you cross the finish line or you might not win.

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Vocabulary lists containing slacken

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Listeners might feel their pulse slacken as they settle into the music’s soothing triple meter, a recurring cycle of one-two-threes.

From The Wall Street Journal • Apr. 29, 2026

You absolutely must allow your lower face to slacken naturally, which may be right around the moment Kardashian parts her artificially plumped lips to make a heroic attempt at acting.

From Salon • Nov. 6, 2025

The report cautioned that it is too early to determine what caused the rate to slacken.

From BBC • Dec. 11, 2024

And, with the tight job market starting to slacken, some predict 2024 will be the year employers finally clamp down.

From Los Angeles Times • Jan. 4, 2024

Although Melynlas did not slacken speed, Taran saw the pace had begun to tell on the other horses.

From "The Black Cauldron" by Lloyd Alexander