a. Slacked, or pulverized, by exposure to the air; as, air-slacked lime. [ 1913 Webster ]

v. t. [ Obs. ] See Forslack. [ 1913 Webster ]

v. t. [ Pref. for- + slack to neglect. ] To neglect by idleness; to delay or to waste by sloth. [ Obs. ] Spenser. [ 1913 Webster ]

n. [ Cf. Slag. ] Small coal; also, coal dust; culm. Raymond. [ 1913 Webster ]

n. [ Icel. slakki a slope on a mountain edge. ] A valley, or small, shallow dell. [ Prov. Eng. ] Grose. [ 1913 Webster ]

a. [ Compar. Slacker superl. Slackest. ] [ OE. slak, AS. sleac; akin to OS. slak, OHG. slah, Prov. G. schlack, Icel. slakr, Sw. slak; cf. Skr. s&rsdot_;j to let loose, to throw. Cf. Slake. ] Lax; not tense; not hard drawn; not firmly extended; as, a slack rope. [ 1913 Webster ]

2. Weak; not holding fast; as, a slack hand. Milton. [ 1913 Webster ]

3. Remiss; backward; not using due diligence or care; not earnest or eager; as, slack in duty or service. [ 1913 Webster ]

The Lord is not slack concerning his promise, as some men count slackness. 2 Pet. iii. 9. [ 1913 Webster ]

4. Not violent, rapid, or pressing; slow; moderate; easy; as, business is slack. “With slack pace.” Chaucer. [ 1913 Webster ]

C&unr_;sar . . . about sunset, hoisting sail with a slack southwest, at midnight was becalmed. Milton. [ 1913 Webster ]

Slack in stays (Naut.), slow in going about, as a ship. --
Slack water, the time when the tide runs slowly, or the water is at rest; or the interval between the flux and reflux of the tide. --
Slack-water navigation, navigation in a stream the depth of which has been increased, and the current diminished, by a dam or dams. [ 1913 Webster ]

Syn. -- Loose; relaxed; weak; remiss; backward; abated; diminished; inactive; slow; tardy; dull. [ 1913 Webster ]

adv. Slackly; as, slack dried hops. [ 1913 Webster ]

n. The part of anything that hangs loose, having no strain upon it; as, the slack of a rope or of a sail. [ 1913 Webster ]

{ } v. i. [ imp. & p. p. Slacked Slackened p. pr. & vb. n. Slacking, Slackening. ] [ See Slack, a. ] 1. 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 ]

2. To be remiss or backward; to be negligent. [ 1913 Webster ]

3. To lose cohesion or solidity by a chemical combination with water; to slake; as, lime slacks. [ 1913 Webster ]

4. To abate; to become less violent. [ 1913 Webster ]

Whence these raging fires
Will slacken, if his breath stir not their flames. Milton. [ 1913 Webster ]

5. To lose rapidity; to become more slow; as, a current of water slackens. [ 1913 Webster ]

6. To languish; to fail; to flag. [ 1913 Webster ]

7. To end; to cease; to desist; to slake. [ Obs. ] [ 1913 Webster ]

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

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

{ } v. t. 1. To render slack; to make less tense or firm; as, to slack a rope; to slacken a bandage. Wycklif (Acts xxvii. 40) [ 1913 Webster ]

2. To neglect; to be remiss in. [ Obs. ] Shak. [ 1913 Webster ]

Slack not the pressage. Dryden. [ 1913 Webster ]

3. To deprive of cohesion by combining chemically with water; to slake; as, to slack lime. [ 1913 Webster ]

4. To cause to become less eager; to repress; to make slow or less rapid; to retard; as, to slacken pursuit; to slacken industry. “Rancor for to slack.” Chaucer. [ 1913 Webster ]

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

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

With such delay
Well plased, they slack their course. Milton. [ 1913 Webster ]

5. 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. Milton. [ 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. [ 1913 Webster ]

n. (Metal.) A spongy, semivitrifled substance which miners or smelters mix with the ores of metals to prevent their fusion. [ Written also slakin. ] [ 1913 Webster ]

adv. In a slack manner. Trench. [ 1913 Webster ]

n. The quality or state of being slack. [ 1913 Webster ]

a. Not slacked; unslaked; as, unslacked lime. [ 1913 Webster ]