Detective is a type of Worker. Detective is a type of Policeman. Policeman is a synonym of Cop. 
Fee is a synonym of Tip. Tip is a synonym of Lean. Lean is a synonym of Tend. 
Worker <--IsA-- Detective --IsA--> Policeman <--Synonym--> Cop 
Fee <--Synonym--> Tip <--Synonym--> Lean <--Synonym--> Tend 