Letter is related to Friend. Afraid is etymologically related to Friend. Afraid is related to Scare. 
Defeat is related to Military. Military is related to Chief. Chief is related to Police. 
Letter <--RelatedTo--> Friend <--EtymologicallyRelatedTo-- Afraid <--RelatedTo--> Scare 
Defeat <--RelatedTo--> Military <--RelatedTo--> Chief <--RelatedTo--> Police 