Joy is related to Inner. Inner is a synonym of Internal. Internal is related to Conscience. 
Pair is the opposite of Single. Single is related to Alone. Alone is related to Island. Island is related to Ocean. 
Joy <--RelatedTo--> Inner <--Synonym--> Internal <--RelatedTo--> Conscience 
Pair <--Antonym--> Single <--RelatedTo--> Alone <--RelatedTo--> Island <--RelatedTo--> Ocean 