Threaten is derived from Threat. Threaten is a type of Warn. Warning is a form of Warn. Warning is related to Duck. 
Class is a synonym of Genre. Genre is related to Rock. you are likely to find Rock in/at/on Chair. 
Threat <--DerivedFrom-- Threaten --IsA--> Warn <--FormOf-- Warning <--RelatedTo--> Duck 
Class <--Synonym--> Genre <--RelatedTo--> Rock --AtLocation--> Chair 