Revolution is related to Freedom. Freedom is a different concept from Slavery. Slavery is the opposite of Liberty. 
Grab is a type of Obtain. Grab is related to Hold. Hold is the opposite of Pass. 
Revolution <--RelatedTo--> Freedom <--DistinctFrom--> Slavery <--Antonym--> Liberty 
Obtain <--IsA-- Grab <--RelatedTo--> Hold <--Antonym--> Pass 