{ } 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 ]