Ignore is the opposite of Rescue. Rescue is related to Purpose. Purpose is the opposite of Mistake. 
Bank is a type of Work. Volunteer is a type of Work. Volunteer is related to Relief. 
Ignore <--Antonym--> Rescue <--RelatedTo--> Purpose <--Antonym--> Mistake 
Bank --IsA--> Work <--IsA-- Volunteer <--RelatedTo--> Relief 