Friend is a synonym of Boyfriend. Boyfriend is a type of Lover. 
Memory is related to Game. Catch is a type of Game. Catch is related to Receive. Receive is a type of Celebrate. 
Friend <--Synonym--> Boyfriend --IsA--> Lover 
Memory <--RelatedTo--> Game <--IsA-- Catch <--RelatedTo--> Receive --IsA--> Celebrate 