Define linear motion?

Question

Please define it in the perspective of physics

Answer 1

linear motion is motion in a straight line.

Like a piston, it goes up and down, as opposed to a wheel that goes round and round (rotational motion).

Answer 2

Linear motion is motion in one dimension.

An example of linear motion is throwing a ball straight up and having it come back straight down. In linear motion there is only an x value to represent displacement, and x varies with t (time).