The passage is from Plato's Plato: Phaedro. 278d4Phaedrus 278d4
The Greek word is philosophos (φιλόσοφος). It is translated by Jowett as lovers of wisdom or philosophers. The original text uses the singular.
The text says literally "The term philosopher or something of this kind fits better to him ..."
The passage is not the origin of the term philosopher. It is used several times in Plato's work. He also uses the verb "philosophein" (φιλοσοφεῖν).