hack driver vs cabby

hack driver and cabby both are nouns.

Word	Noun	Adjective	Verb	Adverb
hack driver	Yes	No	No	No
cabby	Yes	No	No	No

As nouns, hack driver and cabby are synonyms defined as:

Other synonyms of hack driver include cabdriver, cabman, hack-driver, livery driver, taxidriver, taximan.

hack driver (noun)	cabby (noun)
someone who drives a taxi for a living	someone who drives a taxi for a living