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

In the footage, the wooden wall can be seen falling forward with a thud, while two vertical cables hang behind, apparently slack. —Jake Kanter, Deadline, 27 June 2025

Flying Squirrel Trampoline Park, 3305 Corporate Ave, Weston, is an indoor entertainment park with trampolines, dodgeball court, battle beam, climbing walls, ropes course, slack line, dunk hoops, ninja course arcade games, children’s areas (soft-play playground) and the Drey Café. —Rod Stafford Hagwood, Sun Sentinel, 25 June 2025

Noun

Mini David looked every bit of dapper in his black slacks, navy blazer and white button-up shirt. —Elizabeth Ayoola, Essence, 30 Oct. 2025

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

Verb

Tesla is lower by about 17% in 2025, hurt by rising competition and slack demand. —Pia Singh, CNBC, 12 Aug. 2025

Protesters said none of the clothing changes have been put into effect and workers are punished for allegedly slacking in the heat. —Trisha Thomas, Fortune, 24 July 2025