Trap is a type of Design. Device is a type of Design. Device is a synonym of Scheme. 
Secondary is similar to Alternative. Alternative is related to Propose. Propose is related to Marry. 
Trap --IsA--> Design <--IsA-- Device <--Synonym--> Scheme 
Secondary <--SimilarTo--> Alternative <--RelatedTo--> Propose <--RelatedTo--> Marry 