Sentimental alumni upset about closure of Harvard (7)
I believe the answer is:
maudlin
'sentimental' is the definition.
(I know that sentimental can be written as maudlin)
'alumni upset about closure of harvard' is the wordplay.
'upset' is an anagram indicator.
'about' means one lot of letters goes inside another.
'closure of' indicates one should take the final letters.
The last letter of 'harvard' is 'd'.
'alumni' with letters rearranged gives 'maulin'.
'maulin' going around 'd' is 'MAUDLIN'.
(Other definitions for maudlin that I've seen before include "Weakly sentimental" , "Effusively or insincerely emotional" , "lovey-dovey" , "Mawkish" , "Schmaltzy" .)