slack

plural slacks

1. uncountableThe part of anything that hangs loose, having no strain upon it.

   take in the slack

   1 more example

   the slack of a rope or of a sail

2. countableuncountableA dip in a surface.

   […] to make good the voids under the sleeper […] to take out "slacks" in the rail level […]

   1951, Institution of Civil Engineers (Great Britain), Proceedings of the Joint Engineering Conference, 1951, page 45

   2 more examples

   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.

   1858, New South Wales. Parliament. Legislative Council, Votes & Proceedings, page 1020

   […] a road may be kept up to approximately the same level at all times, and a fair surface maintained by rolling in large patches occasionally, as well as opening slacks in the road when they appear and effecting petty repairs. […] a series of slacks will begin to show in the run of the wheels; or […]

   1904, Public Works and Journal of Civil Engineering, page 90

3. countableuncountableIn particular, a shallow dell or hollow; a dip in the surface of terrain, such as between hills.

   Then she became a gay grey mare, / And stood in yonder slack; And he became a gilt saddle, / And sat upon her back.

   1845, Alexander Whitelaw, The Book of Scottish Ballads Collected and Illustrated with Historical and Critical Notices, London : Blackie, page 159

   4 more examples

   Cauldstane Slap, or rather Slack, is a much frequented pass, through which the periodical droves of black cattle are transported into England.

   1815, Alexander Pennecuik, The Works of Alexander Pennecuik ...: Containing the Description of Tweeddale, and Miscellaneous Poems, page 141

   ... for they had at that time observed the side of the brae, where the little green slack was situated, covered with a sheet of flame for a moment.

   1837, James Hogg, The hunt of Eildon. The adventures of Basil Lee. Adam Bell. Duncan Campbell. An old soldier's tale. Katie Cheyne. The long pack. A country funeral. The shepherd's calendar, page 249

   Not that every mountain stream springs from a tarn, but almost every tarn sends out a stream. Then, tarn-hunting teaches the relatively position of places almost as exactly as do the mountain-tops, leading by "backs," and "shoulders," and "slacks," and "feet," and over the lower heights straight to half a dozen seemingly irreconcilable districts[…]

   1864, Elizabeth Lynn Linton, The Lake Country, page 172

   The great interest of the sandhills is the slacks. They are more frequent in some parts than in others, for there are miles where the hollows are all sand and stargrass. But every here and there the hills have receded and formed a little flat valley, where there is something like soil, and where the rain lodges and the mosses grow. This is a "slack;" and in the Lancashire slacks may be found some of the most beautiful […] flowers.

   1880, Littell's Living Age, page 448

4. countableA low-lying marsh or a pool, especially a tidal or intermittent one which periodically fills and drains.

   Modern "moonpreneurs" now hijack tidal slacks to power server farms in Nova Scotia barns, mining Bitcoin during low tides when electricity costs crater.

   (Can we date this quote?), Conrad Riker, Fishing: A Comprehensive Exploration, Conrad Riker

   2 more examples

   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[…]

   1901, The Pall Mall Magazine, page 138

   ... in that quarter lay the great slack of the Watch Hill, the yellow slack that feeds the Blackburn, and in which horse and rider might readily disappear for ever.

   1983 [1897], Ernest Hamilton, The Outlaws of the Marches

   Synonyms: slough

5. uncountableForbearance; lenience; gracious allowance.

   cut [someone] some slack [= cut them a break]

6. uncountablepsychotherapyUnconditional listening attention given by client to patient.

   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."

   1979, Richard Dean Rosen, Psychobabble, page 93

   1 more example

   We have apparently been doing this all our lives, since we were first distressed. This collection of ancient habits seems to be "energized" by the presence, or even the promise, of "slack" or free attention from any person in the situation […]

   1983, Harvey Jackins, The Reclaiming of Power, page 14

7. attributivecountableuncountableAttributive form of slacks (“semi-formal trousers”).

   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.

   1943, Jacob Armstrong Swisher, Iowa in Times of War, State Historical Society of Iowa, page 124

   2 more examples

   Recently though, slack manufacturers have been cuddling under the wings of the clothing industry to a greater extent than ever, for it has become good business to promote separate slacks and sport coats as a coordinated sales unit.

   1970, Harry A. Cobrin, The Men’s Clothing Industry: Colonial Through Modern Times, New York, N.Y.: Fairchild Publications, Inc., →ISBN, page 7

   At that time, it was customary for male college students in Peking to wear long gowns. With a pair of slacks and leather shoes, plus a scarf in the winter, Shu looked very handsome. I tried to wear the gown for two days, and gave it up because I found it difficult to reach the slack pockets under it.

   2004, Pei Pin Han, “Friendship for 54 Years”, in Amy Lanping Sung, Hu Kung-Chung Chien, editors, Shu Chien: Tributes on His 70th Birthday, World Scientific, →ISBN, page 38

comparative slacker · superlative slackest

1. Lax; not tense; not firmly extended.

   a slack rope

2. Weak; not holding fast.

   a slack hand

3. Moderate in some capacity.
   1. Moderately warm.

      a slack oven

   2. Moderate in speed.

      a slack wind

4. Lacking diligence or care; not earnest or eager.

   slack in duty or service

   1 more example

   The Lord is not ſlacke cõcerning his promiſe (as ſome men count ſlackneſſe)[…].

   1611, The Holy Bible, […] (King James Version), London: […] Robert Barker, […], →OCLC, 2 Peter 3:9, column 2

5. Not active or busy, successful, or violent.

   Business is slack.

   3 more examples

   the slack period following the main tourist season

   “They know our boats will stand up to their work,” said Willison, “and that counts for a good deal. A low estimate from us doesn't mean scamped work, but just for that we want to keep the yard busy over a slack time.”

   1928, Lawrence R. Bourne, chapter 3, in Well Tackled!

   In the slack hours the service is maintained by single motor-coaches.

   1940 December, “Notes and News: Waterloo & City Tube Modernisation”, in Railway Magazine, page 668

   Synonyms: slow, moderate, easy

6. Excess; surplus to requirements.

   the slack capacity of an oil pipeline

7. CaribbeanJamaicaslangVulgar; sexually explicit, especially in dancehall music.
8. human sciencesLax.

1. not comparableSlackly.

   slack dried hops

   1 more example

   Her clothes hung slack on her.

present singular third person slacks · participle present slacking · participle past slacked · past slacked

1. ambitransitiveTo slacken.

   In this business of growing rich, poor men […] should slack their pace.

   1692–1717, Robert South, Twelve Sermons Preached upon Several Occasions, volume (please specify |volume=I to VI), London

   1 more example

   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.

   c. 1590 (date written), [John Lyly], Mother Bombie. […], London: […] Thomas Scarlet for Cuthbert Burby, published 1594, →OCLC, Act II, scene ii, signature C3, verso

2. obsoleteTo mitigate; to reduce the strength of.

   Ne did ſhe let dull ſleepe once to relent, / Nor wearineſſe to ſlack her haſt, but fled / Euer alike,[…].

   1590, Edmund Spenser, “Book III, Canto VII”, in The Faerie Queene. […], London: […] [John Wolfe] for William Ponsonbie, →OCLC, stanza 2, page 494

3. To lose cohesion or solidity by a chemical combination with water; to slake.

   Lime slacks.

4. To refuse to work as hard as one is supposed to.

   I can't afford to slack. This job is all I have!

plural slacks

1. rail transportA temporary speed restriction where track maintenance or engineering work is being carried out at a particular place.

   The train runs slowly with frequent slacks for bridge and culvert repairs. At one point occurs the changeover from left- to right-hand running.

   1949 September and October, “The "Nord Express"”, in Railway Magazine, page 336

   2 more examples

   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.

   1939 June, “Pertinent Paragraphs: Pitfalls”, in Railway Magazine, page 456

   A 40 m.p.h. slack at West Ruislip, quickly followed by a 30 m.p.h. slack at Gerrards Cross, increased our lateness to four minutes at High Wycombe.

   1960 February, R. C. Riley, “The London-Birmingham services - Past, Present and Future”, in Trains Illustrated, page 103

plural slacks

1. countableA valley, or small, shallow dell; a sag or saddle in a ridge.

   "I see some folk coming through the slack yonder, […]"

   1871, Walter Scott, Waverly Novels, page 159

   3 more examples

   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; […]

   1812, Walter Scott, Minstrelsy of the Scottish Border: Consisting of Historical and Romantic Ballads Collected in the Southern Counties of Scotland, with a Few of Modern Date Founded Upon Local Tradition, page 246

   […] southward, by the slack of the hill (2,500 feet), west of Ferrowie, (2,628 feet), on the County boundary, and descending by the Capel-burn to the South Esk,[…]

   1875, Alexander Smith, A New History of Aberdeenshire, page 690

   Sheelings : 1. Lies South of the Infields in a Slack betwixt two Hills 2. Lies at the South End of the Loch of Loch Beanoch […]

   1960, John Home, Survey of Assynt

2. 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.

1. uncountablebusinessSmall coal; coal dust.

   It had rather a woolly and uneven beat and was inclined to prime, but there was no trouble with steaming even though the tender contained mostly small slack and dust.

   1959 April, P. Ransome-Wallis, “The Southern in Trouble on the Kent Coast”, in Trains Illustrated, London: Ian Allan Publishing, →ISSN, →OCLC, page 220

   1 more example

   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 […]

   1905, Colliery Engineer, volume 25, page 107

   Synonyms: culm

plural Slacks

1. countableuncountableA surname.
2. A place in England:
   1. countableuncountableA hamlet in Ashover parish, North East Derbyshire district, Derbyshire (OS grid ref SK3362).
   2. countableuncountableA hamlet in Heptonstall parish, Metropolitan Borough of Calderdale, West Yorkshire (OS grid ref SD9828).
   3. countableuncountableA hamlet in the Metropolitan Borough of Kirklees, near Outlane, West Yorkshire (OS grid ref SE0817).
3. InternetcountableuncountablecomputingA real-time collaboration app and platform launched in 2013.

   On Slack, the employees of Strategic Programming chattered about metadata tagging issues.

   2025, Liz Pelly, Mood Machine: The Rise of Spotify and the Costs of the Perfect Playlist, 1st edition, New York: Atria Books, →ISBN