Accident is a synonym of Hazard. Hazard is a synonym of Guess. Guess is a synonym of Hypothesis. Speculation is a type of Hypothesis. 
Aggression is related to Sex. Sex is related to Girl. 
Accident <--Synonym--> Hazard <--Synonym--> Guess <--Synonym--> Hypothesis <--IsA-- Speculation 
Aggression <--RelatedTo--> Sex <--RelatedTo--> Girl 