1
: not using due diligence, care, or dispatch : negligent
2
a
: characterized by slowness, sluggishness, or lack of energy
a slack pace
b
: moderate in some quality
especially
: moderately warm
a slack oven
c
: blowing or flowing at low speed
the tide was slack
3
a
: not tight or taut
a slack rope
b
: lacking in usual or normal firmness and steadiness : weak
slack muscles
slack supervision
4
: wanting in activity : dull
a slack market
5
: lacking in completeness, finish, or perfection
a very slack piece of work
slackly
adverb
slackness
noun
1
: cessation in movement or flow
2
: a part of something that hangs loose without strain
take up the slack of a rope
3
: trousers especially for casual wear
—usually used in plural
4
: a dull season or period
5
a
: a part that is available but not used
some slack in the budget
b
: a portion (as of labor or resources) that is required but lacking
hired a temp to take up the slack
6
: additional leeway or relief from pressure
—usually used with cut
refused to cut me some slack on the schedule
dialectal, England
: a pass between hills
: the finest screenings of coal produced at a mine unusable as fuel unless cleaned
Examples of slack in a Sentence
Adjective
His broken arm hung slack at his side.
The rope suddenly went slack.
He accused the government of slack supervision of nuclear technology.
Verb
They need to stop slacking and get down to work.
the skipper ordered the crew to slack off the sheets on the mainsail
Noun (1)
our boss doesn't cut us any slack when it comes to being back from lunch on time
take up the slack of a rope
she prefers wearing slacks instead of a dress
Recent Examples on the Web
Jonathan A. Czin, Foreign Affairs, 21 Oct. 2025
Oscar Bobb seized on a slack pass and led a counter-attack with Haaland and Reijnders on either side.
—Jordan Campbell, New York Times, 18 Aug. 2025
Aamir Khollam, Interesting Engineering, 7 Oct. 2025
The Amazon rainforest could wither into a savanna; coral reefs could bleach ghost-white; a major current in the Atlantic Ocean might go slack and fail to deliver warmth to Europe, turning Scotland into Siberia.
—Gregory Barber, Quanta Magazine, 15 Sep. 2025
Rachel Trujillo, PEOPLE, 29 Oct. 2025
The two No 10s largely avoid the sort of slack passes and heavy touches that have previously halted United from properly settling into their attacking grooves.
—Carl Anka, New York Times, 26 Oct. 2025
See All Example Sentences for slack
Examples are automatically compiled from online sources to
show current usage.
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Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
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Adjective
With power diffused among top leaders and their allies in the bureaucracy, party discipline was slack.
—Jonathan A. Czin, Foreign Affairs, 21 Oct. 2025
Oscar Bobb seized on a slack pass and led a counter-attack with Haaland and Reijnders on either side.
—Jordan Campbell, New York Times, 18 Aug. 2025
Verb
Conventional mooring setups can easily become overextended or slack as levels shift, forcing operators to perform manual readjustments or face operational risks.
—Aamir Khollam, Interesting Engineering, 7 Oct. 2025
The Amazon rainforest could wither into a savanna; coral reefs could bleach ghost-white; a major current in the Atlantic Ocean might go slack and fail to deliver warmth to Europe, turning Scotland into Siberia.
—Gregory Barber, Quanta Magazine, 15 Sep. 2025
Noun
All three celebs proved how versatile a quarter-zip pullover can be by throwing it on during a relaxing night at home, pairing it with sweatpants for a matching set, and dressing it up with slacks.
—Rachel Trujillo, PEOPLE, 29 Oct. 2025
The two No 10s largely avoid the sort of slack passes and heavy touches that have previously halted United from properly settling into their attacking grooves.
—Carl Anka, New York Times, 26 Oct. 2025
See All Example Sentences for slack
Cite this Entry
“Slack.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/slack. Accessed 30 Oct. 2025.
Copy CitationKids Definition
slack
1 of 3 adjective1
2
: not energetic
a slack pace
4
: not busy
a slack season
slackly
adverb
slackness
noun
slack
2 of 3 verb1
a
: to be or become slack or careless in performing or doing
b
: lessen
the wind slacked off
2
: to avoid work or duty
3
4
a
: to cause to lessen
b
slack
3 of 3 noun1
: a stopping of movement or flow
2
: a part of something that hangs loose without strain
take up the slack of a rope
3
plural
: trousers especially for casual wear
4
: a dull season or period : lull
5
: additional tolerance or relief from pressure
cut me some slack
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