- The definition of an inclined plane is a surface that is at an angle against a horizontal surface.
An example of an inclined plane is a ramp.
This ramp is an inclined plane.
a plane surface set at any angle other than a right angle against a horizontal surface: it is a simple machine that increases mechanical advantage but requires a longer working distance
A plane set at an angle to the horizontal, especially a simple machine used to raise or lower a load by rolling or sliding.
Pushing a load up a gentle slope requires less effort than lifting it.
(plural inclined planes)