Class is related to Subject. Subject is related to Course. Course is related to Meal. 
Nice is related to Friend. Friend is etymologically related to Free. Free is the opposite of Slave. Slave is the opposite of Man. 
Class <--RelatedTo--> Subject <--RelatedTo--> Course <--RelatedTo--> Meal 
Nice <--RelatedTo--> Friend --EtymologicallyRelatedTo--> Free <--Antonym--> Slave <--Antonym--> Man 