The term “sophist” derives from the Greek verb sophizesthai, “to practice wisdom”, and was originally used in a neutral sense, to refer to any exponent of wisdom. According to the 4th-century orator Isocrates, who uses the term to refer invariably to intellectuals whom we would describe as philosophers, Solon was the first Athenian to hold the title of sophist (Antidosis §313). It was actually Plato who introduced the use of the term in our more familiar sense, to describe a certain group of “teachers of wisdom”, or “professionals of intelligence”. These intellectuals were active in the second half of the fifth century BC and professed to educate young Athenians.…
Balla, Chloe. "Sophists". The Literary Encyclopedia. First published 09 October 2009; last revised 30 November -1.
[http://www.litencyc.com/php/stopics.php?rec=true&UID=1527, accessed 20 April 2015.]