The Collaborative International Dictionary of English v.0.48:

Juror \Ju"ror\, n. [F. jureur one who takes oath, L. jurator a
   swearer, fr. jurare, jurari, to swear. See Jury, n.]
   [1913 Webster]
   1. (Law) A member of a jury; a juryman.
      [1913 Webster]

            I shall both find your lordship judge and juror.
                                                  --Shak.
      [1913 Webster]

   2. A member of any jury for awarding prizes, etc.
      [1913 Webster]

WordNet (r) 3.0 (2006):

juror
    n 1: someone who serves (or waits to be called to serve) on a
         jury [syn: juror, juryman, jurywoman]

Bouvier's Law Dictionary, Revised 6th Ed (1856):

JUROR, practice. From juro, to swear; a man who is sworn or affirmed to
serve on a jury.
     2. Jurors are selected from citizens, and may be compelled to serve by
fine; they generally receive a compensation for their services while
attending court they are privileged from arrest in civil cases.