The term "terminable permit" as used in this article shall mean and embrace every grant from a city, town or village of power, right or privilege to occupy or use any of the streets, roads, highways, avenues, parks or public places of such city, town or village for the construction and operation of a street surface railroad, until such time as the city, town or village shall exercise its right to purchase the property, plant and equipment of such street surface railroad in accordance with the provisions of sections one hundred and seventy-three-a to one hundred and seventy-three-h, both inclusive, of this article, or until it shall be otherwise terminated according to law.
N.Y. R.R. Law § 173-A