Pat is etymologically related to Plate. Plate is the opposite of Bowl. Bowl can be used for Hold. Hold is related to Belt. 
Health is related to Illness. Fever is a type of Illness. Fever is related to Medical. Medical is related to Physician. 
Pat --EtymologicallyRelatedTo--> Plate <--Antonym--> Bowl --UsedFor--> Hold <--RelatedTo--> Belt 
Health <--RelatedTo--> Illness <--IsA-- Fever <--RelatedTo--> Medical <--RelatedTo--> Physician 