Stationary
this object that appears to stay in place is a reference point.
It can be said that the net force applied on the object is zero or that the object is in translational equilibrium. Keep in mind that these terms can also be applied if the object is moving at a constant velocity.
Deceleration is merely acceleration in a direction opposite to the original motion. If something isnt moving it cannot be decelerated but if it is moving and the resultant force acts in the opposite direction to motion it will decelerate the object.
Said object is not moving
The answer to the question seems to be clearly given within the question. You have said that the object " ... is moving ... " in a straight line. Therefore we conclude that if you have been honest with us, then the object is certainly in motion.
An object that moves with constant position will have constant velocity or acceleration. This is said to be moving in positive direction and maintains the position.
When an object is moving with different velocity with respect to time then the object is in acceleration or decceleration mode. If the rate of change of velocity is positive then it is said to be accelerated, if its negative it is said to be deaccelerated.
The frictional force needed to just stop something from moving is called limiting friction, and the object is said to be in limiting equilibrium.
the force or other moving object
When an object is moving, it is called kinetic energy.
A skydiver is the fastest moving object in sports.
this isnt scientific, but its called an object.