A title for one who, well, speaks for the dead. In the epilogue to Orson Scott Card's novel Ender's Game, Ender becomes the first Speaker for the buggers, whose entire species was (nearly) just exterminated, and then again for his brother Peter Wiggin, the Hegemon.
The purpose of a Speaker is to investigate the life of a person or persons who has recently died, discover their true nature and motives for their actions and attitudes throughout their life, and speak it to those directly connected to and affected by them. In the case of the bugger Hive Queen and Peter, Ender wrote books that were published throughout humanity for millenia. These books became a sort of Bible for others who became Speakers in later years.
By the time in which Card's novel Speaker for the Dead is set, the occupation of Speaker has been elevated to a sort of interplanetarily-recognized religion -- Speakers may travel to any world, unopposed, once a call has been put out for one to speak a death.