What do Catholic traditions say was the real name of St. Thomas?

The Gospels do not mention the real name of St Thomas, unlike in the case of other apostles. The name Thomas (Koine Greek: Θωμᾶς) given for the apostle in the Gospels is derived from the Aramaic or Syriac: ܬܐܘܡܐ‎ *Toma*, equivalently from Hebrew *Teom*, meaning "twin". The equivalent term for twin in Greek, which is also used in the New Testament, is Δίδυμος Didymus. {Courtesy: Wikipedia} So, if Didymus and Thomas were in fact nick-names, what was the real name of St Thomas the Apostle? **What do Catholic traditions have to say on this?**