Noah Webster's Dictionary 1. (v.) To become slack; to be made less tense, firm, or rigid; to decrease in tension; as, a wet cord slackens in dry weather. 2. (v.) To be remiss or backward; to be negligent. 3. (v.) To lose cohesion or solidity by a chemical combination with water; to slake; as, lime slacks. 4. (v.) To abate; to become less violent. 5. (v.) To lose rapidity; to become more slow; as, a current of water slackens. 6. (v.) To languish; to fail; to flag. 7. (v.) To end; to cease; to desist; to slake. 8. (v. t.) To render slack; to make less tense or firm; as, to slack a rope; to slacken a bandage. 9. (v. t.) To neglect; to be remiss in. 10. (v. t.) To deprive of cohesion by combining chemically with water; to slake; as, to slack lime. 11. (v. t.) To cause to become less eager; to repress; to make slow or less rapid; to retard; as, to slacken pursuit; to slacken industry. 12. (v. t.) To cause to become less intense; to mitigate; to abate; to ease. 13. (n.) A spongy, semivitrifled substance which miners or smelters mix with the ores of metals to prevent their fusion.

Multi-Version Concordance Slacken (1 Occurrence) 2 Kings 4:24 Then she saddled an ass, and said to her servant, Drive, and go forward; slacken me not the riding, except I bid thee. (See JPS ASV RSV)