Professor shares unopened gifts (9)
I believe the answer is:
donations
'gifts' is the definition.
(I know this)
'professor shares unopened' is the wordplay.
'professor' becomes 'don' (term for a university professor).
'shares' becomes 'rations' (ration is a kind of share).
'unopened' means to remove the first letter (the opening of the word is removed).
'rations' with its initial letter removed is 'ations'.
'don'+'ations'='DONATIONS'
(Other definitions for donations that I've seen before include "Gifts" , "Contributions" .)