ostracize
To purposely leave someone out and treat them like nothing.
To ostracize someone means to deliberately exclude them from a group or community, treating them as if they don't exist. When kids ostracize a classmate, they might refuse to sit with them at lunch, leave them out of games at recess, or pretend not to hear when they speak. It's a form of social rejection that can feel devastating to the person being shut out.
While we don't literally exile people anymore, the emotional effect remains the same: being ostracized means being pushed outside the circle where you want to belong.
People sometimes ostracize others because of differences, jealousy, or just following what the group does without thinking. A new student with an unusual accent might be ostracized, or someone who stands up to a bully might find themselves suddenly excluded.
Being ostracized differs from simply not being invited to something. Ostracism is active and deliberate: the group works together to make someone feel unwelcome and isolated. It's one of the cruelest things people do to each other because humans naturally need connection and belonging.