The word "most heathenish" means extremely savage, uncivilized, or barbaric. There are various synonyms for this word, including pagan, godless, uncultured, uncivilized, and savage. Other synonyms for it can be wild, brutal, or primitive. The term can also be used to describe people who are not religious or do not have any beliefs in god or deity. It can be applied to manners, customs, or practices that are considered unacceptable or primitive in today's society. In short, "most heathenish" is a strong term used to describe extreme behaviors that go against social norms and values.