SLACKS

noun

1. The part of anything that hangs loose, having no strain upon it.
2. A tidal marsh or shallow that periodically fills and drains.

verb

1. To slacken.
2. To mitigate; to reduce the strength of.
3. To lose cohesion or solidity by a chemical combination with water; to slake.

noun

1. A temporary speed restriction where track maintenance or engineering work is being carried out at a particular place.