Consider flow over a fixed horizontal flat plate. at the plate's surface the fluid velocity is reduced to zero. this is

The zero-velocity of the fluid in a horizontal flat plate is due to the no slipping condition.  

Explanation:

As the flat plate is considering at rest and in the surface, the fluid and plate velocities must be equal due to the no slipping condition then the velocity of the flow is also null. In fact, the surface of the plate acts decelerating the fluid velocity making it stop at the point of contact.