talesman (n.)
"reserve member of a jury," 1670s, from tales "writ ordering bystanders to serve" in place of jurors not in attendance (late 15c.), via Anglo-French (mid-13c.), from Latin tales (in tales de circumstantibus "such persons from those standing about," a clause featured in such a writ), noun use of plural of talis "such, of such kind" (see that).