IPA: /ˈprɒs.ə.lɪ.taɪ.zər/
KK: /ˈprɑsəˌlɪˌtaɪzər/
A person who tries to persuade others to change their beliefs, especially in religion or politics.
The proselytizer spoke passionately about his faith to anyone who would listen.
Proselytizer → It is formed from "proselyte" (from Greek "proselytos", meaning a newcomer or one who has come over) and "-izer" (a suffix used to indicate a person who performs a specific action). The word "proselytizer" refers to a person who actively seeks to convert others to a particular faith or belief system.
Think of someone who is a 'newcomer' ('proselyte') and is actively trying to bring others into their beliefs — that's what a proselytizer does.