sophist
noun
soph·ist ˈsä-fist 
1
: philosopher
2
capitalized : any of a class of ancient Greek teachers of rhetoric, philosophy, and the art of successful living prominent about the middle of the fifth century b.c. for their adroit subtle and allegedly often specious reasoning
3
: a captious or fallacious reasoner
Example Sentences
Recent Examples on the Web In Plato’s most famous dialogue, the Republic, Socrates falls into conversation with the bold and intimidating Thrasymachus, who is a sophist—that is, one who offers instructions on how to argue a case, no matter its merit. 
Rebecca Newberger Goldstein, WSJ, 15 Mar. 2018 Not even the most shameless sophist will argue that anything like that happened. Hugh Hewitt, The Denver Post, 10 Mar. 2017
Rebecca Newberger Goldstein, WSJ, 15 Mar. 2018 Not even the most shameless sophist will argue that anything like that happened. Hugh Hewitt, The Denver Post, 10 Mar. 2017 Word History
Etymology
Latin sophista, from Greek sophistēs, literally, expert, wise man, from sophizesthai to become wise, deceive, from sophos clever, wise
First Known Use
14th century, in the meaning defined at sense 1