What do we mean by translatory motion?

Hint- Use the concept that rectilinear motion and curvilinear motion comes under the subcategory of translatory motion.

Complete step by step answer:
Translatory motion –
The motion in which every point on the moving body moves through the same distance in the same interval of time is called Translatory motion.
Translatory motion are of two types –
Rectilinear motion and curvilinear motion.
According to E.T. Whittaker “If a body is moved from one position to another, and if the lines joining the initial and final points of each of the points of the body are a set of parallel straight lines of length (l), so that the orientation of the body in space is unaltered, the displacement is called a translation parallel to the direction of the lines, through a distance (l).”
Example of rectilinear motion is:
A bullet fired from the gun.
Here all the points of the body which are in motion are in the same direction.
So this is the required answer.

Note – In the subcategory of it, in rectilinear motion the body travels in a straight line whereas in curvilinear motion the body travels in a curved path, thus in rectilinear motion the velocity can remain uniform whereas in curvilinear motion the velocity keeps on changing its direction.