1. Not tense; not hard drawn; not firmly extended; as a slack rope; slack rigging; slack shrouds.
2. Weak; remiss; not holding fast; as a slack hand.
3. Remiss; backward; not using due diligence; not earnest or eager; as slack in duty or service; slack in business.
4. Not violent; not rapid; slow; as a slack pace.
, n. A valley or small shallow dell.