Terror is a synonym of Threat. Threat is related to Danger. Danger is related to Situation. 
Horse is related to Beast. Beast is the opposite of Human. Clerk is a type of Human. 
Terror <--Synonym--> Threat <--RelatedTo--> Danger <--RelatedTo--> Situation 
Horse <--RelatedTo--> Beast <--Antonym--> Human <--IsA-- Clerk 