Oppose is related to Protest. Protest is related to Bad. Bad is the opposite of Adequate. Adequate is a synonym of Just. 
Police is a synonym of Patrol. Patrol is etymologically related to Path. Path is related to Sidewalk. 
Oppose <--RelatedTo--> Protest <--RelatedTo--> Bad <--Antonym--> Adequate <--Synonym--> Just 
Police <--Synonym--> Patrol --EtymologicallyRelatedTo--> Path <--RelatedTo--> Sidewalk 