“Put out of the synagogue”
His parents said this because they were afraid of the Jews. For the Jews had already determined that anyone who confessed Jesus as the Christ would be put out of the synagogue. (John 9:22 BSB)
What it sounds like today
Losing a membership; inconvenient but survivable.
The cultural key
The synagogue was not one appointment in the week; it was the community's civic center: school, court, welfare system, market reputation, and social world in one. Aposynagōgos (a word found only in John: here, 12:42, 16:2) meant excommunication from all of it, civic death for a village family. That is why the healed man's parents, interrogated about their own son's cure, answer like witnesses under threat: 'He is of age; ask him.'
Recovered meaning
The story's quiet heroism: a beggar blind from birth gains his eyes and loses his community the same week, expelled for refusing to un-say what happened to him. The Gospel adds the ending the synagogue could not see: 'Jesus heard that they had cast him out, and having found him' took him in.