Thomas the doubting Apostle tho·mast·he·doubtingapostle uncommon noun 1. the Apostle who would not believe the resurrection of Jesus until he saw Jesus with his own eyes SynonymsThomasSaint ThomasSt. Thomasdoubting ThomasThomas the doubting Apostle Related words Broader terms Apostlesaint WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.