Die is the opposite of Birthday. Birthday is related to Date. Date is related to Romantic. 
Oil is related to Middle. Middle is related to Peasant. Peasant is the opposite of Royal. Royal is related to Purple. 
Die <--Antonym--> Birthday <--RelatedTo--> Date <--RelatedTo--> Romantic 
Oil <--RelatedTo--> Middle <--RelatedTo--> Peasant <--Antonym--> Royal <--RelatedTo--> Purple 