Outer is related to Skin. Skin is related to Body. Body is related to Physical. Physical is the opposite of Mental. 
you are likely to find Toilet in/at/on Hospital. Clinic is part of Hospital. Clinic is a type of Session. Session is related to Lesson. 
Outer <--RelatedTo--> Skin <--RelatedTo--> Body <--RelatedTo--> Physical <--Antonym--> Mental 
Toilet --AtLocation--> Hospital <--PartOf-- Clinic --IsA--> Session <--RelatedTo--> Lesson 