Fuss over unusual discharge (6)
I believe the answer is:
rumpus
'fuss' is the definition.
(thesaurus)
'over unusual discharge' is the wordplay.
'over' is a charade indicator (letters next to each other).
'unusual' becomes 'rum' (I've seen this before).
'discharge' becomes 'pus' (I've seen this before).
'rum' put next to 'pus' is 'RUMPUS'.
(Other definitions for rumpus that I've seen before include "Noisy, disruptive commotion" , "To-do" , "Hullabaloo" , "'Commotion, din (6)'" , "Uproar or angry dispute" .)