Garbage is related to Waste. Waste is related to Mind. Mind is related to Dream. Dream is related to Imagine. 
Relative is related to Child. Child is related to Mother. Mother is related to Formal. Formal is the opposite of Informal. 
Garbage <--RelatedTo--> Waste <--RelatedTo--> Mind <--RelatedTo--> Dream <--RelatedTo--> Imagine 
Relative <--RelatedTo--> Child <--RelatedTo--> Mother <--RelatedTo--> Formal <--Antonym--> Informal 