Barker gets a degree in theological doctrine (5)
I believe the answer is:
dogma
'theological doctrine' is the definition.
'dogma' can be an answer for 'doctrine' (dogma is a kind of doctrine). I am unsure of the 'theological' bit.
'barker gets a degree' is the wordplay.
'barker' becomes 'dog' (I've seen this in another clue).
'gets' is a charade indicator (letters next to each other).
'a degree' becomes 'MA' (Master of Arts is a type of degree).
'dog'+'ma'='DOGMA'
'in' is the link.
Can you help me to learn more?
(Other definitions for dogma that I've seen before include "church teaching" , "Fixed belief" , "Some believe it certainly" , "Code of belief" , "Authoritative doctrine" .)