hack-driver vs cabdriver

hack-driver and cabdriver both are nouns.

Word	Noun	Adjective	Verb	Adverb
hack-driver	Yes	No	No	No
cabdriver	Yes	No	No	No

As nouns, hack-driver and cabdriver are synonyms defined as:

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

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