Thadeus \th(a)-deus\ as a boy's name is a variant of Thaddeus (Aramaic), and the meaning of Thadeus is "heart".

The baby name Thadeus sounds like Thaddius, Thaddaus and Thaddaeus. Other similar baby names are Theseus, Thonus, Mateus, Thad, Thady and Thaddaos.