For the purpose of this chapter the following words and phrases shall have the following meanings ascribed to them respectively:
(A) DRIVER. The person in actual physical control of a taxicab.
(B) OPERATOR. Any person owning, in charge of, or managing a taxicab business in the city.
(C) TAXICAB. Any vehicle whose owner or driver secures or accepts passengers for hire on the public streets, or in public or quasi-public places, except motorbuses.
(D) UNENGAGED TAXICAB. A taxicab in charge of a driver and neither occupied by or standing at the direction of a passenger nor responding to a call of a prospective passenger. A taxicab standing in a taxi stand shall be presumed to be unengaged.
('68 Code, § 52.2)