Volume is related to Weight. Weight is related to Object. Object is related to Structure. Rib is a type of Structure. 
Large is the opposite of Little. Little is related to Piece. 
Volume <--RelatedTo--> Weight <--RelatedTo--> Object <--RelatedTo--> Structure <--IsA-- Rib 
Large <--Antonym--> Little <--RelatedTo--> Piece 