add. ·noun the teaching of isaac thomas hecker (1819-88), which interprets catholicism as promoting human aspirations after liberty and truth, and as the religion best suited to the character and institutions of the american people.
2. heckerism ·add. ·noun improperly, certain views or principles erroneously ascribed to father hecker in a french translation of elliott's life of hecker. they were condemned as "americanism" by the pope, in a letter to cardinal gibbons, january 22, 1899.