Therefore contributing to the greater good (4)
I believe the answer is:
ergo
'therefore' is the definition.
(thesaurus)
'contributing to the greater good' is the wordplay.
'contributing to' says the answer is hidden in the clue.
'ERGO' is hidden in the letters of 'greater good'.
(Other definitions for ergo that I've seen before include "for this reason" , "Thus" , "so philosopher wrote in Latin" , "as a consequence" , "'Cogito, ---- sum'" .)