Crowd is related to Term. Term is a synonym of Boundary. 
Acid is a type of Compound. Compound is a type of Account. Account is related to Safe. Safe is related to Metal. 
Crowd <--RelatedTo--> Term <--Synonym--> Boundary 
Acid --IsA--> Compound --IsA--> Account <--RelatedTo--> Safe <--RelatedTo--> Metal 