1. a substance that slows down or stops a chemical reaction or process
Usage: technical; chemistry
2. a device or mechanism that stops or restrains motion or action
Usage: technical; engineering

Examples

• The arrestant in the paint formulation prevents premature curing.
• Engineers installed an arrestant to control the speed of the descent.
• The chemical arrestant extended the shelf life of the product.
• A mechanical arrestant was added to the system for safety purposes.
• The arrestant reduced the reaction rate significantly.