Two females beam after a disturbance of the peace (6)
I believe the answer is:
affray
'disturbance of the peace' is the definition.
(I've seen this before)
'two females beam after a' is the wordplay.
'two females' becomes 'ff'.
'beam' becomes 'ray' ('ray' can be a synonym of 'beam'**).
'after' says to put letters next to each other.
'ff'+'ray'='ffray'
'ffray' after 'a' is 'AFFRAY'.
(Other definitions for affray that I've seen before include "Noisy disturbance" , "Breach of peace through public fighting" , "Disturbance of the peace" , "Noisy quarrel" , "Breach of the peace; brawl, fight" .)