cabman vs livery driver

cabman and livery driver both are nouns.

Word	Noun	Adjective	Verb	Adverb
cabman	Yes	No	No	No
livery driver	Yes	No	No	No

As nouns, cabman and livery driver are synonyms defined as:

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

cabman (noun)	livery driver (noun)
someone who drives a taxi for a living	someone who drives a taxi for a living