Shunning

persistently avoid, ignore, or reject (someone or something) through antipathy or caution.

https://en.wikipedia.org/wiki/Shunning

"Shunning can be the act of social rejection, or emotional distance. In a religious context, shunning is a formal decision by a denomination or a congregation to cease interaction with an individual or a group, and follows a particular set of rules. It differs from, but may be associated with, excommunication.

Social rejection occurs when a person or group deliberately avoids association with, and habitually keeps away from an individual or group...

Mental rejection is a more individual action, where a person subconsciously or willfully ignores an idea, or a set of information related to a particular viewpoint. Some groups are made up of people who shun the same ideas."