• (n.) One of a sacerdotal college of fifteen men whose chief duty was to take care of the Sibylline books.
Quin`de·cem'vir noun ; plural English Quindecemvirs , Latin Quindecemviri . [ Latin , from quindecim fifteen + vir a man.] (Rom. Antiq.) One of a sacerdotal college of fifteen men whose chief duty was to take care of the Sibylline books. 
quindecemvir A member of a body, commission, etc., of fifteen men; especially one of the priests who had charge of the Sibylline books.