Real Dictionary

sophist in American English
in ancient Greece, any of a group of teachers of rhetoric, politics, philosophy, etc., some of whom were notorious for their clever, specious arguments
noun: any of a class of professional teachers in ancient Greece who gave instruction in various fields, as in general culture, rhetoric, politics, or disputation

sophist in British English
noun: one of the pre-Socratic philosophers who were itinerant professional teachers of oratory and argument and who were prepared to enter into debate on any matter however specious