slacken

• POS: Verb (usu participle)
• HYPHEN: slack=en

CIDE DICTIONARY

slacken, v. i. [See Slack, a.].

•  To become slack; to be made less tense, firm, or rigid; to decrease in tension; as, a wet cord slackens in dry weather.  [1913 Webster]
•  To be remiss or backward; to be negligent.  [1913 Webster]
•  To lose cohesion or solidity by a chemical combination with water; to slake; as, lime slacks.  [1913 Webster]
•  To abate; to become less violent.  [1913 Webster]

  "Whence these raging fires
  Will slacken, if his breath stir not their flames."  [1913 Webster]
•  To lose rapidity; to become more slow; as, a current of water slackens.  [1913 Webster]
•  To languish; to fail; to flag.  [1913 Webster]
•  To end; to cease; to desist; to slake.  [1913 Webster]

  "That through your death your lineage should slack."  [1913 Webster]

  "They will not of that firste purpose slack."  [1913 Webster]

slacken, v. t. 

•  To render slack; to make less tense or firm; as, to slack a rope; to slacken a bandage.  Wycklif (Acts xxvii. 40)  [1913 Webster]
•  To neglect; to be remiss in.  Shak.  [1913 Webster]

  "Slack not the pressage."  [1913 Webster]
•  To deprive of cohesion by combining chemically with water; to slake; as, to slack lime.  [1913 Webster]
•  To cause to become less eager; to repress; to make slow or less rapid; to retard; as, to slacken pursuit; to slacken industry.  Chaucer.  [1913 Webster]

  "I should be grieved, young prince, to think my presence
  Unbent your thoughts, and slackened 'em to arms."  [1913 Webster]

  "In this business of growing rich, poor men should slack their pace."  [1913 Webster]

  "With such delay
  Well plased, they slack their course."  [1913 Webster]
•  To cause to become less intense; to mitigate; to abate; to ease.  [1913 Webster]

  "To respite, or deceive, or slack thy pain
  Of this ill mansion."  [1913 Webster]

Air-slacked lime, lime slacked by exposure to the air, in consequence of the absorption of carton dioxide and water, by which it is converted into carbonate of lime and hydrate of lime.

slacken, n. 

 A spongy, semivitrifled substance which miners or smelters mix with the ores of metals to prevent their fusion.  [1913 Webster]

OXFORD DICTIONARY

slacken, v.tr. & intr. make or become slack.

Idiom

slacken off = slack off (see SLACK(1)).

THESAURUS

slacken

abate, allay, alleviate, anesthetize, appease, arrest, assuage, attemper, attenuate, backpedal, backwater, bank the fire, bate, benumb, block, blunt, bog down, bottle up, brake, chasten, check, clip the wings, come apart, confine, constrain, control, countercheck, curb, cushion, dam up, damp, dampen, de-emphasize, deaden, deaden the pain, decelerate, degenerate, delay, detain, deteriorate, die down, diffuse, dilute, diminish, disimprove, disintegrate, disjoin, disperse, dissolve into chaos, downplay, drag, draw rein, dull, ease, ease matters, ease off, ease up, ebb, extenuate, fall, fall back, foment, free, get worse, give relief, grow worse, hang up, hinder, hold back, hold in check, hold up, impede, inhibit, intercept, interfere, intermeddle, interrupt, intervene, keep back, keep in check, keep within bounds, lag, lax, lay, lenify, lessen, let down, let go, let up, let up on, lighten, loose, loosen, lose ground, lose momentum, lose speed, lull, make late, meddle, mire, mitigate, moderate, modulate, mollify, numb, obstruct, obtund, oppose, pad, palliate, play down, poultice, pour balm into, pour oil on, reduce, reduce the temperature, reef, regress, rein in, relapse, relax, relent, relieve, remit, repress, resist, restrain, retard, retrograde, retrogress, salve, scatter, scotch, set back, sicken, slack, slack off, slack up, slackening, slake, slip back, slow, slow down, slow up, slow-up, smother, snub, sober, sober down, soften, soothe, stay, stifle, stop, stupe, subdue, subside, suppress, take in sail, tame, temper, throttle down, tone down, tune down, unbend, unbrace, underplay, unglue, unlax, unleash, unstick, unstrain, unstring, untighten, untune, unwind, wane, water down, weaken, worsen

ROGET THESAURUS

slacken

Incoherence

VB make loose, loosen, slacken, relax, unglue, detach.

Repose

VB repose, rest, rest and be thankful, take a rest, take one's ease, take it easy, relax, unbend, slacken, take breath, rest upon one's oars, pause, stay one's hand, lie down, recline, recline on a bed of down, recline on an easy chair, go to rest, go to bed, go to sleep, take a holiday, shut up shop, lie fallow.

Hindrance

VB hinder, impede, filibuster, impedite, embarrass, keep off, stave off, ward off, obviate, avert, antevert, turn aside, draw off, prevent, forefend, nip in the bud, retard, slacken, check, let, counteract, countercheck, preclude, debar, foreclose, estop, inhibit, shackle, restrict, obstruct, stop, stay, bar, bolt, lock, block, block up, choke off, belay, barricade, block the way, bar the way, stop the way, forelay, dam up, put on the brake, scotch the wheel, lock the wheel, put a spoke in the wheel, put a stop to, traverse, contravene, interrupt, intercept, oppose, hedge in, hedge round, cut off, inerclude, interpose, interfere, intermeddle, cramp, hamper, clog, clog the wheels, cumber, encumber, incumber, handicap, choke, saddle with, load with, overload, lay, lumber, trammel, tie one's hands, put to inconvenience, incommode, discommode, discompose, hustle, corner, drive into a corner, run foul of, fall foul of, cross the path of, break in upon, thwart, frustrate, disconcert, balk, foil, faze, feaze, feeze, baffle, snub, override, circumvent, defeat, spike guns, spoil, mar, clip the wings of, cripple, put an extinguisher on, damp, dishearten, discountenance, throw cold water on, spoil sport, lay a wet blanket, throw a wet blanket on, cut the ground from under one, take the wind out of one's sails, undermine, be in the way of, stand in the way of, act as a drag, hang like a millstone round one's neck.

Moderation

VB be moderate, keep within bounds, keep within compass, sober down, settle down, keep the peace, remit, relent, take in sail, moderate, soften, mitigate, temper, accoy, attemper, contemper, mollify, lenify, dulcify, dull, take off the edge, blunt, obtund, sheathe, subdue, chasten, sober down, tone down, smooth down, weaken, lessen, check palliate, tranquilize, pacify, assuage, appease, swag, lull, soothe, compose, still, calm, calm down, cool, quiet, hush, quell, sober, pacify, tame, damp, lay, allay, rebate, slacken, smooth, alleviate, rock to sleep, deaden, smooth, throw cold water on, throw a wet blanket over, turn off, slake, curb, tame, smooth over, pour oil on the waves, pour oil on the troubled waters, pour balm into, mattre de l'eau dans son vin, go out like a lamb, roar you as gently as any sucking dove.

Slowness

VB move slowly, creep, crawl, lag, slug, drawl, linger, loiter, saunter, plod, trudge, stump along, lumber, trail, drag, dawdle, grovel, worm one's way, steal along, job on, rub on, bundle on, toddle, waddle, wabble, slug, traipse, slouch, shuffle, halt, hobble, limp, caludicate, shamble, flag, falter, trotter, stagger, mince, step short, march in slow time, march in funeral procession, take one's time, hang fire, retard, relax, slacken, check, moderate, rein in, curb, reef, strike sail, shorten sail, take in sail, put on the drag, apply the brake, clip the wings, reduce the speed, slacken speed, slacken one's pace, lose ground.