When it comes to finding synonyms for the word "hack-driver," there are several options to choose from. One synonym for hack-driver is "cabby," meaning someone who drives a taxi. Another option is "carriage driver," indicating someone who drives a horse-drawn carriage. Additionally, there is the term "cab driver," which is similar to cabby, but may suggest a more professional driver. Other synonyms include "taxi driver," "hire car driver," and "chauffeur." Overall, there are plenty of synonyms to choose from when referring to someone who drives vehicles for hire, from horse-drawn carriages to modern-day taxis.