from The American Heritage® Dictionary of the English Language, 4th Edition

  • adj. Moving slowly; sluggish: a slack pace.
  • adj. Lacking in activity; not busy: a slack season for the travel business.
  • adj. Not tense or taut; loose: a slack rope; slack muscles. See Synonyms at loose.
  • adj. Lacking firmness; flaccid: a slack grip.
  • adj. Lacking in diligence or due care or concern; negligent: a slack worker. See Synonyms at negligent.
  • adj. Flowing or blowing with little speed: a slack current; slack winds.
  • adj. Linguistics Pronounced with the muscles of the tongue and jaw relatively relaxed; lax.
  • transitive v. To make slower or looser; slacken.
  • transitive v. To be careless or remiss in doing: slack one's duty.
  • transitive v. To slake (lime).
  • intransitive v. To be or become slack.
  • intransitive v. To evade work; shirk.
  • n. A loose part, as of a rope or sail.
  • n. A lack of tension; looseness.
  • n. A period of little activity; a lull.
  • n. A cessation of movement in a current of air or water.
  • n. An area of still water.
  • n. Unused capacity: still some slack in the economy.
  • n. Casual trousers that are not part of a suit.
  • adv. In a slack manner: a banner hanging slack.
  • slack off To decrease in activity or intensity.
  • idiom cut Slang To make an allowance for (someone), as in allowing more time to finish something.
  • n. A mixture of coal fragments, coal dust, and dirt that remains after screening coal.
  • n. Chiefly British A small dell or hollow.
  • n. Chiefly British A bog; a morass.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. Small coal; coal dust.
  • n. A valley, or small, shallow dell.
  • n. The part of anything that hangs loose, having no strain upon it.
  • n. A tidal marsh or shallow, that periodically fills and drains.
  • adj. Lax; not tense; not hard drawn; not firmly extended.
  • adj. Weak; not holding fast.
  • adj. Remiss; backward; not using due diligence or care; not earnest or eager.
  • adj. Not violent, rapid, or pressing.
  • adv. Slackly.
  • v. To mitigate; to reduce the strength of.
  • v. to procrastinate; to be lazy
  • v. to refuse or dislike exerting effort

from the GNU version of the Collaborative International Dictionary of English

  • adj. Lax; not tense; not hard drawn; not firmly extended.
  • adj. Weak; not holding fast.
  • adj. Remiss; backward; not using due diligence or care; not earnest or eager.
  • adj. Not violent, rapid, or pressing; slow; moderate; easy.
  • adv. Slackly.
  • n. Small coal; also, coal dust; culm.
  • n. A valley, or small, shallow dell.
  • n. The part of anything that hangs loose, having no strain upon it.
  • intransitive v. To become slack; to be made less tense, firm, or rigid; to decrease in tension.
  • intransitive v. To be remiss or backward; to be negligent.
  • intransitive v. To lose cohesion or solidity by a chemical combination with water; to slake.
  • intransitive v. To abate; to become less violent.
  • intransitive v. To lose rapidity; to become more slow.
  • intransitive v. To languish; to fail; to flag.
  • intransitive v. To end; to cease; to desist; to slake.
  • transitive v. To render slack; to make less tense or firm.
  • transitive v. To neglect; to be remiss in.
  • transitive v. To deprive of cohesion by combining chemically with water; to slake.
  • transitive v. To cause to become less eager; to repress; to make slow or less rapid; to retard.
  • transitive v. To cause to become less intense; to mitigate; to abate; to ease.

from The Century Dictionary and Cyclopedia

  • Slow in movement; tardy.
  • Slow in flow; sluggish or at rest: as, slack water: specifically noting the tide, or the time when the tide is at rest—that is, between the flux and reflux.
  • Slow in action; lacking in promptness or diligence; negligent; remiss.
  • Not tight; not tense or taut; relaxed; loose: as, a slack rope; slack rigging; a slack rein; figuratively, languid; limp; feeble; weak.
  • Not compacted or firm; loose.
  • Lacking in briskness or activity; dull: said especially of business.
  • In hydraulic engineering, a pool or pond behind a dam serving for needs of navigation. Such ponds are used with a series of dams and locks, to render small streams navigable.
  • Synonyms Careless, dilatory, tardy, inactive.
  • n. The part of a rope or the like that hangs loose, having no stress upon it; also, looseness, as of the parts of a machine.
  • n. A remission; an interval of rest, inactivity, or dullness, as in trade or work; a slack period.
  • n. A slack-water haul of the net: as, two or three slacks are taken daily.
  • n. A long pool in a streamy river.
  • In a slack manner; slowly; partially; insufficiently: as, slack dried hops; bread slack baked.
  • To become slack or slow; slacken; become slower: as, a current of water slacks.
  • To become less tense, firm, or rigid; decrease in tension.
  • To abate; become less violent.
  • To become languid; languish; fail; flag.
  • To make slack or slow; retard.
  • To make slack or less tense; loosen; relax: as, to slack a rope or a bandage.
  • To relax; let go the hold of; lose or let slip.
  • To make less intense, violent, severe, rapid, etc.; abate; moderate; diminish; hence, to mitigate; relieve.
  • To be remiss in or neglectful of; neglect.
  • To make remiss or neglectful.
  • To slake (lime). See slake, transitive verb, 3.
  • To cool in water.
  • To retard the speed of, as a railway-train.
  • n. The finer screenings of coal; coal-dirt; especially, the dirt of bituminous coal.
  • n. A sloping hillside.
  • n. An opening between hills; a hollow where no water runs.
  • n. A common.
  • n. A morass.
  • n. The interval of slack water, when the tide is at rest, either at high or low tide; sluggishness of the current, at that time See slack, adjective, 2.
  • n. plural A sailor's loose trousers.
  • n. Feeble, foolish talk.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • v. be inattentive to, or neglect
  • v. cause to heat and crumble by treatment with water
  • v. become slow or slower
  • v. make less active or intense
  • adj. not tense or taut
  • v. release tension on
  • n. dust consisting of a mixture of small coal fragments and coal dust and dirt that sifts out when coal is passed over a sieve
  • n. a soft wet area of low-lying land that sinks underfoot
  • adj. flowing with little speed as e.g. at the turning of the tide
  • n. the quality of being loose (not taut)
  • v. make less active or fast
  • adj. lacking in rigor or strictness
  • v. avoid responsibilities and work, be idle
  • n. a cord or rope or cable that is hanging loosely
  • v. become less in amount or intensity
  • n. a noticeable deterioration in performance or quality
  • n. a stretch of water without current or movement


from The American Heritage® Dictionary of the English Language, 4th Edition

Middle English slak, from Old English slæc.
Middle English sleck.
Middle English slak, from Old Norse slakki.


  • His eyes were dark and blank, his expression slack.

    Heaven Lake

  • The forenoon being what he called his slack time he found the earlier part of it most profitably used for sleep.

    The Dust Flower

  • About ten minutes or so, those tugs, five tugs in all, were pulling with all their might to try and get this old gray lady off of Pier 86 and finally, as we stood on the flight deck, there was movement, very slow at first, and then she just took off and she was traveling faster than I think they expected and we ended up just sitting off of the Bayone wet dock for about three hours waiting for what they call slack to decrease or lower tide to come in so the ship could be controlled better and brought right into this dock that we are obviously just now moving into.

    CNN Transcript Dec 5, 2006

  • The argument that continued monetary slack is necessary to add millions more jobs scares those of us who are skeptical about the wisdom of Keynesian micromanagement in general.

    Interest Rate Debate, Arnold Kling | EconLog | Library of Economics and Liberty

  • Casting up, and not too far out, stripping in slack as the line moves back towards you will bet you the deepest.

    Split shot

  • [Garner's] style, conversational but never slack, is natural, supple, and exact, her way of seeing is acute and sympathetic, you receive an instant impression of being in the company of a congenial friend and it is impossible not to follow her as she brings to life the events and feelings she is exploring ....

    The Spare Room: Summary and book reviews of The Spare Room by Helen Garner.

  • But a month or two at mimimum wage gives the chance to learn while getting some slack from the boss because you aren't getting paid that much.

    The Minimum Wage, Arnold Kling | EconLog | Library of Economics and Liberty

  • She urged the horse by suddenly leaning forward with her body, at the same time, for an instant, letting the rein slack and touching the neck with her bridle hand.

    Jack London's Short Story - Planchette

  • "The whole point of the Stimulus was that state and local governments would be able to hire people and pick up some of the slack from the private sector."

    Guess who isn't getting laid off (Jack Bog's Blog)

  • Gaze in slack jawed wonder at the scene below involving a killer light fixture.

    Weekly Mishmash: November 23-29 :


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