Leave is a type of Permission. Consent is a type of Permission. Consensus is etymologically related to Consent. 
Drink is related to Liquid. Sauce is a type of Liquid. Sauce is related to Apple. 
Leave --IsA--> Permission <--IsA-- Consent <--EtymologicallyRelatedTo-- Consensus 
Drink <--RelatedTo--> Liquid <--IsA-- Sauce <--RelatedTo--> Apple 