Tartar's hierarchy (5)
I believe the answer is:
scale
I believe this is a double definition.
'tartar's' is the first definition.
(thesaurus)
'hierarchy' is the second definition.
(I've seen this before)
(Other definitions for scale that I've seen before include "Plate protecting the skin of fish and reptiles" , "Tones rising maybe" , "Graduated table" , "Relative magnitude" , "Weigh up" .)