Rip is a synonym of Steal. Steal is a different concept from Buy. Buy is the opposite of Sell. 
Iron is a type of Color. Color is related to Ingredient. Ingredient is a synonym of Part. Part is related to Floor. 
Rip <--Synonym--> Steal <--DistinctFrom--> Buy <--Antonym--> Sell 
Iron --IsA--> Color <--RelatedTo--> Ingredient <--Synonym--> Part <--RelatedTo--> Floor 