Expert leading academic division, in short (5)
I believe the answer is:
adept
'expert' is the definition.
(adept is a kind of expert)
'leading academic division in short' is the wordplay.
'leading' suggests taking the first letters (the leading letter of the word).
'division in short' becomes 'dept' (I can't justify this - if you can you should believe this answer much more).
The initial letter of 'academic' is 'a'.
'a'+'dept'='ADEPT'
Can you help me to learn more?
(Other definitions for adept that I've seen before include "who gets the lapis philosophicus secret" , "One highly skilled could be taped" , "Practised" , "capable" , "Skilled, expert" .)