Frontier is a type of Discipline. Discipline is a synonym of Order. Order is related to Council. 
Drown is a type of Eliminate. Eliminate is a synonym of Exclude. Exclude is a synonym of Shut. 
Frontier --IsA--> Discipline <--Synonym--> Order <--RelatedTo--> Council 
Drown --IsA--> Eliminate <--Synonym--> Exclude <--Synonym--> Shut 