Medicine is a synonym of Prescription. Prescription is a type of Direction. Direction is related to Voice. 
Average is related to Like. Like is related to City. City is related to Apple. Apple is related to Round. 
Medicine <--Synonym--> Prescription --IsA--> Direction <--RelatedTo--> Voice 
Average <--RelatedTo--> Like <--RelatedTo--> City <--RelatedTo--> Apple <--RelatedTo--> Round 