The word "tillerman" refers to the person who steers a boat or ship by manipulating the tiller. Synonyms for this word include helmsman, steersman, pilot, coxswain, and boatman. Helmsman is a commonly used synonym for tillerman, particularly in nautical contexts. Steersman is also a good choice and can be used interchangeably with tillerman. Other synonyms like pilot, coxswain, and boatman are more general terms that describe someone who navigates watercrafts or guides passengers. Regardless of the synonym used, anyone referred to as a tillerman, helmsman, or steersman is responsible for safely steering a vessel.