mid-15c., Paraclit, a title of the Holy Spirit, from Old French paraclet (13c.), from Medieval Latin paracletus, from a Church Latin rendering of Greek paraklētos "advocate, intercessor, legal assistant," noun use of an adjective meaning "called to one's aid," from parakalein "to call to one's aid," in later use "to comfort, to console," from para (see para- (1)) + kalein "to call" (from PIE root *kele- (2) "to shout").
[I]n the widest sense, a helper, succorer, aider, assistant; so of the Holy Spirit destined to take the place of Christ with the apostles (after his ascension to the Father), to lead them to a deeper knowledge of gospel truth, and to give them the divine strength needed to enable them to undergo trials and persecutions on behalf of the divine kingdom .... [Thayer, "A Greek-English Lexicon of the New Testament," 1889]
But also sometimes translated in English bibles as Advocate, on the notion of "intercession." The word was earlier borrowed directly from Latin as paraclitus (early 13c.).