First-year divinity student's a sweetie! (9)

I believe the answer is:

refresher

I'm a little stuck... Click here to teach me more about this clue!

'a sweetie' is the definition.
(sweets with sherbet centre)

'first-year divinity student's' is the wordplay.
'first-year divinity' becomes 're' (Re is an example. I am not sure about the 'first-year' bit.).
'student' becomes 'fresher' (fresher is a kind of student).
're'+'fresher'='REFRESHER'

Can you help me to learn more?

(Other definitions for refresher that I've seen before include "Type of course" , "one kind of course" , "Top-up course" , "course of sorts" , "drink" .)

I've seen this clue in The Everyman puzzle in The Observer.

Want a hint initially instead of a full solution? Install my app