Slender student beastly doctor admits in south-east (6)
I believe the answer is:
svelte
'slender' is the definition.
(synonyms)
'student beastly doctor admits in south-east' is the wordplay.
'student' becomes 'l' (as in L-plates for learner drivers).
'beastly doctor' becomes 'vet' (vetting is a kind of doctoring. I am not sure about the 'beastly' bit.).
'admits' is an insertion indicator.
'in' indicates putting letters inside.
'south east' becomes 'se'.
'l' put within 'vet' is 'velt'.
'velt' going into 'se' is 'SVELTE'.
Can you help me to learn more?
(Other definitions for svelte that I've seen before include "Slim and stylish" , "Lithe and lissom" , "Sylphlike" , "Elegant and of slender build" , "Slim or slender in a graceful way" .)