Barabbas was the criminal who was freed in place of Jesus as recorded in all four Gospels (Matt 27:15-26), (Mark 15:6-15), (Luke 23:13–25), (John 18:38-19:16). Slated to be crucified, he was released as was part of the Passover custom when the crowd chose him to be freed over Jesus.
Though the name is simply stated in the Gospels, behind the Greek of the original Gospels stands the Aramaic of the day of Jesus. And there the irony can be seen. Barabbas means in Aramaic "Son of a (the) Father".