Smell is a type of Perceive. Smell is a synonym of Sense. 
Essence is related to Core. Core is a type of Set. Set is related to Distinguish. Distinguish is related to Difference. 
Perceive <--IsA-- Smell <--Synonym--> Sense 
Essence <--RelatedTo--> Core --IsA--> Set <--RelatedTo--> Distinguish <--RelatedTo--> Difference 