The part of anything that hangs loose, having no strain upon it.
take in the slack
A tidal marsh or shallow that periodically fills and drains.
To slacken.
To mitigate; to reduce the strength of.
To lose cohesion or solidity by a chemical combination with water; to slake.
Lime slacks.
A temporary speed restriction where track maintenance or engineering work is being carried out at a particular place.
A valley, or small, shallow dell.
Semi-formal trousers that are less formal than those part of a suit but suitable for wearing in most offices and therefore nowadays no longer considered casual trousers. (Takes a plural verb even when referring to a single pair; may be referred to as a pair of slacks)