Synonyms of slack

slack 1 of 3

adjective

ˈslak 

1

as in lazy

failing to give proper care and attention

a building contractor known mainly for his firm's slack workmanship and slipshod construction

Synonyms & Similar Words

• lazy
• careless
• neglectful
• neglecting
• negligent
• lax
• derelict
• reckless
• remiss
• disregardful
• oblivious
• irresponsible
• forgetful
• heedless
• incautious
• inattentive
• thoughtless
• unguarded
• unmindful
• disinterested
• delinquent
• loose
• uninterested
• apathetic
• wild
• unthinking
• indifferent
• unwary
• unconcerned
• disregarding
• unheeding

Antonyms & Near Antonyms

• careful
• conscientious
• attentive
• cautious
• nonnegligent
• punctilious
• meticulous
• circumspect
• responsible
• regarding
• painstaking
• watchful
• wary
• mindful
• vigilant
• chary
• guarded
• alert
• thinking
• observant
• interested
• thoughtful
• gingerly
• provident
• heedful
• concerned
• regardful
• heeding
• forethoughtful
• foresighted

2

as in flexible

not bound by rigid standards

slack supervision on the project

Synonyms & Similar Words

• flexible
• relaxed
• sloppy
• careless
• loose
• lax
• unrestricted
• easygoing
• lazy
• unrestrained
• negligent
• irresponsible
• slovenly
• neglectful
• slipshod
• heedless
• remiss
• derelict
• sloven
• unfussy

Antonyms & Near Antonyms

• hard
• severe
• rigid
• stern
• strict
• harsh
• tight
• rigorous
• restricted
• careful
• restrained
• exact
• conscientious
• constrained
• meticulous
• scrupulous
• inflexible
• fussy
• punctilious
• painstaking
• implacable

3

as in loosened

not tightly fastened, tied, or stretched

left the ropes slack

Synonyms & Similar Words

• loosened
• loose
• lax
• relaxed
• undone
• insecure
• unsecured
• slackened
• detached
• untied
• unbound
• unattached
• free
• baggy
• unfastened
• saggy
• blousy

Antonyms & Near Antonyms

• tight
• taut
• tense
• restrained
• constrained
• bound
• attached
• tied
• fast
• firm
• stuck
• fastened
• jammed
• wedged
• snug

slack

2 of 3

noun

1

as in latitude

an allowable margin of freedom or variation

our boss doesn't cut us any slack when it comes to being back from lunch on time

Synonyms & Similar Words

• latitude
• leeway
• space
• wiggle room
• rein
• license
• swing

2

as in slackness

the extent to which something hangs or dips below a straight line

take up the slack of a rope

Synonyms & Similar Words

• slackness
• sag
• droop
• hang
• laxness
• looseness
• laxity
• limpness
• floppiness

Antonyms & Near Antonyms

• tension
• rigidity
• tightness
• tenseness
• tautness
• rigidness

3

as in pants

slacks plural an outer garment covering each leg separately from waist to ankle

she prefers wearing slacks instead of a dress

Synonyms & Similar Words

• pants
• trousers
• jeans
• britches
• breeches
• pantaloons
• denims
• blue jeans
• hose
• cords
• corduroys
• cargo pants
• pants suit
• sweatpants
• baggies
• knee breeches
• pantsuit
• bell-bottoms
• knickerbockers
• legging
• bloomers

slack

3 of 3

verb

as in to loosen

to make less taut

the skipper ordered the crew to slack off the sheets on the mainsail

Synonyms & Similar Words

• loosen
• slacken
• relax
• ease
• untie
• detach
• free
• undo
• unfasten
• unbind

Antonyms & Near Antonyms

• tension
• stretch
• tighten
• tense
• strain
• bind
• tie
• attach
• restrain
• fasten
• constrain

Synonym Chooser

How is the word slack different from other adjectives like it?

Some common synonyms of slack are lax, neglectful, negligent, and remiss. While all these words mean "culpably careless or indicative of such carelessness," slack implies want of due or necessary diligence or care.

slack workmanship

When might lax be a better fit than slack?

While in some cases nearly identical to slack, lax implies a blameworthy lack of strictness, severity, or precision.

a reporter lax about accurate quotation

When could neglectful be used to replace slack?

The words neglectful and slack can be used in similar contexts, but neglectful adds a more disapproving implication of laziness or deliberate inattention.

a society callously neglectful of the poor

In what contexts can negligent take the place of slack?

While the synonyms negligent and slack are close in meaning, negligent implies inattention to one's duty or business.

negligent about writing a note of thanks

When is it sensible to use remiss instead of slack?

The synonyms remiss and slack are sometimes interchangeable, but remiss implies blameworthy carelessness shown in slackness, forgetfulness, or neglect.

had been remiss in their familial duties

Example Sentences

Recent Examples of slack

Adjective

That’s why trains have a trick called slack action. —Rhett Allain, Wired News, 10 Mar. 2026

But what happens when the detox is over and the chorus of text pings, slack dings and social media notifications swells throughout the rest of the year? —Deborah Vankin, Los Angeles Times, 13 Jan. 2026

Noun

This first test series of the summer has been regarded as a fresh start for England and its under-pressure leadership after a 4-1 loss to Australia during an Ashes tour featuring reports of excessive drinking and when England was accused of slack preparation and a wrong tactical approach. —ABC News, 7 June 2026

Even if that worked for Palm Beach County, there are no similar millionaire clusters in poor counties to pick up the slack. —Sun Sentinel Editorial Board, Sun Sentinel, 6 June 2026

Verb

Nitibhon, a Thai supermodel, plays her tycoon as comically drab, keeping her gaunt cheeks slack to emphasize her character’s hollowness. —Amy Nicholson, Los Angeles Times, 4 Feb. 2026

Does no slack in sales volume, despite higher DRAM prices, hurt the case? —Jim Cramer, CNBC, 25 Jan. 2026