Merriam-Webster Collegiate Dictionary - talesman

 noun  Etymology: Middle English tales talesmen, from Medieval Latin tales de circumstantibus such (persons) of the bystanders; from the wording of the writ summoning them  Date: 1679  1. a person added to a jury usually from among bystanders to make up a deficiency in the available number of jurors  2. a member of a large pool of persons called for jury duty from which jurors are selected