Student tucking into French bread that's unseasoned (5)
I believe the answer is:
plain
'unseasoned' is the definition.
Both the answer and definition are adjectives. Perhaps you can see an association between them that I can't see?
'student tucking into french bread' is the wordplay.
'student' becomes 'L' (as in L-plates for learner drivers).
'tucking into' means one lot of letters goes inside another.
'french bread' becomes 'pain' (I've seen this before).
'l' going within 'pain' is 'PLAIN'.
'that's' acts as a link.
Can you help me to learn more?
(Other definitions for plain that I've seen before include "Ordinary; flat region" , "Not decorated" , "Obvious - ordinary" , "lament" , "Not elaborate; clear" .)