wheelbase

As a noun wheelbase

is the horizontal distance between the front and rear axles of a road or rail vehicle.

As an adjective undefined is

lacking a definition or value.

As nouns the difference between wheelbase and trackwidth

is that wheelbase is the horizontal distance between the front and rear axles of a road or rail vehicle while trackwidth is the width of a track.

As nouns the difference between taxonomy and wheelbase

is that taxonomy is the science or the technique used to make a classification while wheelbase is the horizontal distance between the front and rear axles of a road or rail vehicle.