pros·elyt·ize proselytizes proselytizing proselytized in BRIT, also use proselytise If you proselytize, you try to persuade someone to share your beliefs, especially religious or political beliefs. I assured him we didn't come here to proselytize Christians were arrested for trying to convert people, to proselytise them. to try to persuade someone to join a religious group, political party etc - used especially when you disapprove of this