When a particle is slowing down, its velocity is decreasing over time. This means that its speed is reducing or it might even come to rest at some point.
Related terms
Velocity: Velocity describes how fast an object's position changes with respect to time. It includes both the magnitude (speed) and direction.
Acceleration: Acceleration measures how quickly an object's velocity changes over time. If acceleration is negative, it indicates deceleration or slowing down.
Speed: Speed refers to the rate at which an object moves without considering its direction.