Contribute is a synonym of Assist. Protect is a type of Assist. Protect is related to Provide. Horse is a type of Provide. 
Hour is a synonym of Stroke. Cut is a type of Stroke. 
Contribute <--Synonym--> Assist <--IsA-- Protect <--RelatedTo--> Provide <--IsA-- Horse 
Hour <--Synonym--> Stroke <--IsA-- Cut 