Corn is related to Indian. Indian is related to American. American is related to Continent. Continent is related to Measurement. 
Odd is the opposite of Common. Common is a different concept from Unique. 
Corn <--RelatedTo--> Indian <--RelatedTo--> American <--RelatedTo--> Continent <--RelatedTo--> Measurement 
Odd <--Antonym--> Common <--DistinctFrom--> Unique 