Thieves, The two

(Luke 23:32, 39-43), robbers, rather brigands, probably followers of Barabbas. Our Lord's cross was placed between those of the "malefactors," to add to the ignominy of his position. According to tradition, Demas or Dismas was the name of the penitent thief hanging on the right, and Gestas of the impenitent on the left.

Noah Webster's New International Dictionary of the English Language

(n.) Plural of Thief.