Republic is related to Nation. Nation is related to Freedom. Freedom is the opposite of Slavery. 
Champion is a synonym of Supporter. Supporter is related to Neck. Neck is related to Spine. Spine is a type of Bone. 
Republic <--RelatedTo--> Nation <--RelatedTo--> Freedom <--Antonym--> Slavery 
Champion <--Synonym--> Supporter <--RelatedTo--> Neck <--RelatedTo--> Spine --IsA--> Bone 