What does "slack" mean?
The part of anything that hangs loose, having no strain upon it.
Slack
/slæk/ adj, adv, name, noun, verb, slang
adj, adv, name, noun, verb, slang ·Top 500 ·Elementary level
Meaning at a glance
- Primary sense: The part of anything that hangs loose, having no strain upon it.
- Grammar: slack is listed as adj, adv, name, noun, verb, slang.
- Nearest alternatives: slackness, abandon, abate, abate.
- Useful contrasts: stiff, catalan tensió, everready.
- Usage evidence: We tend to slack off after many hours of hard work.
How to use "slack"
- Start with the primary definition, then check the part of speech before placing the word in a sentence.
- Compare nearby synonyms to make sure "slack" carries the exact meaning, tone, and strength you need.
- Use the example sentence as a context check. If your sentence uses the word differently, confirm that the grammar still fits.
Meaning check
- Does the word fit the sentence's grammar?
- Does it match the intended tone rather than only the dictionary definition?
- Would a simpler synonym be clearer for the reader?
- Is there enough surrounding context to prevent ambiguity?
Source and review context
This entry combines structured lexical data with WordToolSet review checks. Definitions, examples, synonyms, and usage notes may come from different source tables, so the page is designed to show evidence from more than one angle before you rely on "slack" in a final draft.
If a word has several senses, prefer the sense that matches your sentence's grammar and surrounding context. A correct definition can still be the wrong choice when the sentence needs a different register, emphasis, or level of specificity.
Before you rely on this definition
Read the first definition as a starting point, then check the example, synonyms, and part of speech before treating "slack" as the right word for your sentence.
If your draft is formal, technical, persuasive, or sensitive, compare "slack" with a nearby alternative so the final choice matches both meaning and reader expectation.
Compare nearby meanings
- Use synonyms when you need a softer, stronger, simpler, or more specific word.
- Use antonyms to check the boundary of the meaning and avoid accidental contrast.
- Use the example sentence to confirm the word behaves naturally in context.
- Keep the original wording when a replacement adds complexity without improving precision.
Definition decision workflow
1. Identify the role
Check whether "slack" is acting as adj, adv, name, noun, verb, slang in your sentence. A definition is only useful when the grammar matches the way the word is being used.
2. Test the nearest option
Compare it with "slackness" and other nearby choices to see whether the sentence needs a softer, stronger, or more familiar word.
3. Confirm with context
Use the example sentence below as an evidence check, then read your own sentence out loud to catch tone or rhythm problems.
Review note: Definition pages are checked for source coverage, sentence evidence, synonym support, and editorial insight before they are treated as approval-ready pages. If the evidence is too thin, the page remains available to users but is kept out of the approval-facing indexed inventory.
Final meaning check
Before publishing a sentence with "slack", ask whether the word helps the reader understand the idea faster. A precise word should reduce confusion, not simply make the sentence look more polished.
When the definition, synonym evidence, and example context point in the same direction, the word is usually a safer choice. When they conflict, revise the sentence or choose a clearer alternative.
Definitions
Noun
- 1 The part of anything that hangs loose, having no strain upon it. uncountable
"the slack of a rope or of a sail"
- 2 A temporary speed restriction where track maintenance or engineering work is being carried out at a particular place.
"This pitfall, beginning in February and finishing in May, resulted in a drop of about 3 ft. in the platform level; during this period it was necessary to level the track three times weekly, and impose a service slack of 15 m.p.h. The subsidence appears now to have finished, and normal speed is once again permitted."
- 3 A valley, or small, shallow dell; a sag or saddle in a ridge. countable
"Red Ringan sped, and the spearmen led, Up Goranberry Slack; Aye, many a wight, unmatched in fight, Who never more came back. And bloody set the westering sun, And bloody rose he up; […]"
- 4 Small coal; coal dust. uncountable
"One of the important improvements of recent years has been attained by mixing the peat pulp as it passes through the grinding machine, with other inflammable materials, such as bituminous coal dust, or slack […]"
- 5 a cord or rope or cable that is hanging loosely wordnet
Show 11 more definitions
- 6 A dip in a surface. countable, uncountable
"Richardson states that a low joint, a short distance from Haslam's Creek Bridge, was, in his opinion, the cause of the accident. […] [He] told Morgan, the Permanent Way Inspector, that there was a "slack" in the road on the Parramatta side of Haslam's Creek Bridge, […] I can positively state […] There was no such slack. The road was in as good running condition as I would wish to see any road. On all lines of course there are slacks, but not slacks of a serious nature; and that there was any such slack or depression in the rails as spoken of by Richardson I positively deny."
- 7 A flat-bottomed, hollow zone within a sand-dune system that has developed over impervious strata, sometimes due to erosion or blow-out of the dune system; its flat base level is therefore close to or at the permanent water-table level, and therefore has rich, marshy flora, with Salix species (willows) as typical woody colonisers.
- 8 the quality of being loose (not taut) wordnet
- 9 In particular, a shallow dell or hollow; a dip in the surface of terrain, such as between hills. countable, uncountable
"Cauldstane Slap, or rather Slack, is a much frequented pass, through which the periodical droves of black cattle are transported into England."
- 10 a soft wet area of low-lying land that sinks underfoot wordnet
- 11 A low-lying marsh or a pool, especially a tidal or intermittent one which periodically fills and drains. countable
"The "slacks" I have mentioned are fresh-water pools which extend just inside the outer sandhills. Being mostly dry in summer, the shore fowl love to breed there. Peewits nest on their banks, and the long grasses and sand willow[…]"
- 12 a stretch of water without current or movement wordnet
- 13 Unconditional listening attention given by client to patient. uncountable
"The counselor is directed to give his client "free attention," or "slack," performing a kind of vigil, a version of Carl Rogers's "unconditional positive regard.""
- 14 a noticeable deterioration in performance or quality wordnet
- 15 Attributive form of slacks (“semi-formal trousers”). attributive, countable, form-of, uncountable
"The breeches formerly worn with those spiral leggings have been succeeded by full length, slack-type trousers which are loose at the knee and around the calf."
- 16 dust consisting of a mixture of small coal fragments and coal dust and dirt that sifts out when coal is passed over a sieve wordnet
Verb
- 1 To slacken. ambitransitive
"I maruell I heare no nevves of Dromio, either hee ſlackes the matter, or betrayes his maiſter, I dare not motion anie thing to Stellio, till I knovve vvhat my boy hath don; Ile hunt him out, if the loiterſacke be gone ſpringing into a tauerne, Ile fetch him reeling out."
- 2 cause to heat and crumble by treatment with water wordnet
- 3 To mitigate; to reduce the strength of. obsolete
"Ne did ſhe let dull ſleepe once to relent, / Nor wearineſſe to ſlack her haſt, but fled / Euer alike,[…]."
- 4 become less in amount or intensity wordnet
- 5 To lose cohesion or solidity by a chemical combination with water; to slake.
"Lime slacks."
Show 7 more definitions
- 6 make less active or intense wordnet
- 7 To refuse to work as hard as one is supposed to.
"I can't afford to slack. This job is all I have!"
- 8 become slow or slower wordnet
- 9 make less active or fast wordnet
- 10 release tension on wordnet
- 11 be inattentive to, or neglect wordnet
- 12 avoid responsibilities and work, be idle wordnet
Adjective
- 1 Lax; not tense; not firmly extended.
"a slack rope"
- 2 Weak; not holding fast.
"a slack hand"
- 3 Moderate in some capacity.; Moderately warm.
"a slack oven"
- 4 Moderate in some capacity.; Moderate in speed.
"a slack wind"
- 5 Lacking diligence or care; not earnest or eager.
"slack in duty or service"
Show 4 more definitions
- 6 Not active or busy, successful, or violent.
"Business is slack."
- 7 Excess; surplus to requirements.
"the slack capacity of an oil pipeline"
- 8 Vulgar; sexually explicit, especially in dancehall music. Caribbean, Jamaica, slang
- 9 Lax.
Adjective
- 1 lacking in rigor or strictness wordnet
- 2 flowing with little speed as e.g. at the turning of the tide wordnet
- 3 not tense or taut wordnet
Adverb
- 1 Slackly. not-comparable
"slack dried hops"
Proper Noun
- 1 A surname. countable, uncountable
- 2 A place in England:; A hamlet in Ashover parish, North East Derbyshire district, Derbyshire (OS grid ref SK3362). countable, uncountable
- 3 A place in England:; A hamlet in Heptonstall parish, Metropolitan Borough of Calderdale, West Yorkshire (OS grid ref SD9828). countable, uncountable
- 4 A place in England:; A hamlet in the Metropolitan Borough of Kirklees, near Outlane, West Yorkshire (OS grid ref SE0817). countable, uncountable
- 5 A real-time collaboration app and platform launched in 2013. Internet, countable, uncountable
"On Slack, the employees of Strategic Programming chattered about metadata tagging issues."
Example
"We tend to slack off after many hours of hard work."
Common questions
What is a synonym for "slack"?
Common synonyms include: slackness, abandon, abate, abate, abatement, abeyant.
How do you use "slack" in a sentence?
We tend to slack off after many hours of hard work.
How do you pronounce "slack"?
Pronounced /slæk/.
Etymology
Etymology 1
From Middle English slak, from Old English slæc (“slack”), from Proto-Germanic *slakaz. For sense of coal dust, compare slag.
Etymology 2
From Middle English slakken, slaken, from Old English slacian, from Proto-Germanic *slakōną (“to slack, slacken”).
Etymology 3
Either from the adjective in Etymology 1 or the verb in Etymology 2.
Etymology 4
From Middle English slak, from Old Norse slakki (“a slope”). Cognate with Icelandic slakki, Norwegian slakke.
Etymology 5
Of unknown origin. Possibly related to Middle Dutch slacke or Middle Low German slecke. Doublet of slag.
Etymology 6
* As an English and Dutch surname, from the adjective slack. * Also as an English surname, from the noun slack (“shallow valley”). * Possibly also a Slovene surname Americanized from slak (“bindweed”), from Proto-Slavic *sъvolkъ. * The name of the software is an acronym of Searchable Log of All Conversation and Knowledge.