auditor (n.) Look up auditor at Dictionary.com
early 14c., "official who receives and examines accounts;" late 14c., "a hearer, one who listens," from Anglo-French auditour (Old French oieor "listener, court clerk," 13c.; Modern French auditeur), from Latin auditor "a hearer, a pupil, scholar, disciple," in Medieval Latin "a judge, examiner of accounts," from auditus, past participle of audire "to hear" (see audience). The process of receiving and examining accounts formerly was done, and vouched for, orally. Related: Auditorial.