1. a device or substance that slows down or reduces the speed of something
Usage: commonly used in physics, engineering, and automotive contexts
2. in nuclear physics, a substance that slows down neutrons in a nuclear reactor
Usage: technical; also called a moderator

Examples

• The car's decelerator system engaged smoothly when the driver pressed the brake pedal.
• Engineers designed a new decelerator to improve stopping distance on the highway.
• Water serves as a decelerator in nuclear reactors, slowing down fast neutrons.
• The spacecraft used a decelerator parachute to slow its descent through the atmosphere.
• Modern vehicles rely on advanced decelerators for safety and efficiency.
• The decelerator reduced the particle beam's energy before it reached the target.