Efficient is a synonym of Effective. Effective is related to Real. Real is a different concept from Dream. 
Fall is related to Dead. Dead is related to Hay. Hay is related to Dried. 
Efficient <--Synonym--> Effective <--RelatedTo--> Real <--DistinctFrom--> Dream 
Fall <--RelatedTo--> Dead <--RelatedTo--> Hay <--RelatedTo--> Dried 