The term "un-Protestantize" refers to the act of reversing or undoing the process of adopting Protestant beliefs or practices. While there are no direct synonyms for this specific term, there are related terms that convey similar concepts. One alternative could be "re-Catholicize", which signifies the return to Catholicism from Protestantism. Another potential synonym is "de-Protestantize", which highlights the removal of Protestant influences and restoring previous religious affiliations. These terms suggest the actions of transitioning away from Protestantism rather than focusing solely on the word "un-Protestantize". Although synonyms don't precisely replicate this specific term, they capture its essence within the broader context of religious beliefs and practices.