As used in this chapter, the following terms shall have the meanings indicated:
Includes any automobile or motor vehicle commonly called "taxi," engaged in the business of carrying passengers for hire which is held out, announced or advertised to operate or run over the public streets or highways in the borough and particularly accepts and discharges passengers who may offer themselves for transportation from points or places within the borough to points or places within or without the borough, but not operated over a fixed route. Nothing in this definition or chapter shall apply to omnibuses.