Graduates get hard thump (4)
I believe the answer is:
bash
'thump' is the definition.
(thesaurus)
'graduates get hard' is the wordplay.
'graduates' becomes 'bas' (people with Bachelor of Arts degrees).
'get' is a charade indicator (letters next to each other).
'hard' becomes 'h' (abbreviation used in pencil classifications).
'bas'+'h'='BASH'
(Other definitions for bash that I've seen before include "Party (colloq.)" , "Smite; a party" , "Break - party" , "social occasion" , "Social event - clobber" .)