Follow Master of Arts principle (5)
I believe the answer is:
dogma
'principle' is the definition.
(thesaurus)
'follow master of arts' is the wordplay.
'follow' becomes 'dog' (I've seen this before).
'master of arts' becomes 'ma' ('MA' can be a synonym of 'master of arts').
'dog'+'ma'='DOGMA'
(Other definitions for dogma that I've seen before include "A religious belief" , "Item of belief" , "Some believe it certainly" , "Doctrine accepted without question" , "Doctrine put forward as true, not to be questioned" .)