Meaning: Its source is an Aramaic expression meaning "Heart."

Languages: This boy's name is used in English and Latin.

Nicknames: Tad and Thad

Non-English Forms: Tadeusz, Taddeo, Thaddaios, Thaddej, Taco, Tako and Tadeu

Popularity: The name Thaddeus ranked 822nd in popularity for males of all ages in a sample of 2000-2003 Social Security Administration statistics and 611th in popularity for males of all ages in a sample of the 1990 US Census.

Though this name appears on the 1990 U.S. Census lists, it is used by only a small percentage of the general population.

Narrative: This was a byname for one of the twelve disciples of Jesus in Christian scriptures. It distinguished two men who shared the first name Judas, the other being Judas Iscariot, the disciple who betrayed Jesus.

In Matthew, his personal name is given as Lebbaeus, another Aramaic name roughly equivalent to Thaddeus. However, in Luke he is called Judas, and scholars believe this was his true personal name.

The task of accurately translating the name is difficult. Terms such as ''nipple'' or ''bosom'' are sometimes used. These are reminiscent of the ancient folk practice of exposing the nipple as a crude gesture of friendship and trust. However, some believe this name simply derives from Theodorus, meaning ''God's gift.''