What is the meaning of Turnpike?

A frame consisting of two bars crossing each other at right angles and turning on a post or pin, to hinder the passage of animals, but admitting a person to pass between the arms; a turnstile.

A gate or bar set across a road to stop carriages, animals, and sometimes people, until a toll is paid,

A winding stairway.

A beam filled with spikes to obstruct passage; a cheval de frise.

A toll road, especially a toll expressway.

A trajectory on a finite time interval that satisfies an optimality criterion which is associated with a cost function.

To form (a road, etc.) in the manner of a turnpike road, or into a rounded form, as the path of a road.

A young female gymnast

Source: wiktionary.org