Sick is a different concept from Health. Health is related to Safety. Safety is related to Regulation. Regulation is etymologically related to Regulate. 
Street is related to Alley. 
Sick <--DistinctFrom--> Health <--RelatedTo--> Safety <--RelatedTo--> Regulation --EtymologicallyRelatedTo--> Regulate 
Street <--RelatedTo--> Alley 