Improved is similar to Better. Best is etymologically related to Better. Best is related to Achievement. 
Permission is derived from Mission. Mission is a type of Work. Work is etymologically related to Surgeon. 
Improved <--SimilarTo--> Better <--EtymologicallyRelatedTo-- Best <--RelatedTo--> Achievement 
Permission --DerivedFrom--> Mission --IsA--> Work --EtymologicallyRelatedTo--> Surgeon 