Ass is a synonym of Butt. Butt is part of Body. Body is related to Matter. Matter is a synonym of Topic. 
Body is a type of Life. Life is a synonym of Biography. 
Ass <--Synonym--> Butt --PartOf--> Body <--RelatedTo--> Matter <--Synonym--> Topic 
Body --IsA--> Life <--Synonym--> Biography 