Thaddeaus is a distinctive boys' name in United States, ranking #10040 in 2005 with 7 recorded births. This places Thaddeaus in the bottom 25% of ranked US boys' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2001 with 10 births ranking #6885. In 2005, approximately 1 in every 285,307 boys born was named Thaddeaus. FALLING Recent data shows the name is currently falling.