1. To become slack; to be made less tense, firm, or rigid; to decrease in tension; as, a wet cord slackens in dry weather. 2. To be remiss or backward; to be negligent. 3. To lose cohesion or solidity by a chemical combination with water; to slake; as, lime slacks. 4. To abate; to become less violent. Whence these raging fires Will slacken, if his breath stir not their ...
