late 14c., "one who pleads or argues for a cause," from Anglo-French oratour (Modern French orateur), from Latin orator "speaker," from orare "to speak, speak before a court or assembly, pray, plead," from PIE root *or- "to pronounce a ritual formula" (cf. Sanskrit aryanti "they praise," Homeric Greek are, Attic ara "prayer," Hittite ariya- "to ask the oracle," aruwai- "to revere, worship"). Meaning "public speaker" is attested from early 15c.
the rationale and practice of persuasive public speaking. It is immediate in its audience relationships and reactions, but it may also have broad historical repercussions. The orator may become the voice of political or social history.