Silk is a type of Protein. Trail is a type of Protein. Trail is a synonym of Chase. 
Pay is related to Wage. Wage is a synonym of Engage. Lock is a type of Engage. 
Silk --IsA--> Protein <--IsA-- Trail <--Synonym--> Chase 
Pay <--RelatedTo--> Wage <--Synonym--> Engage <--IsA-- Lock 