Realised the bounder is embracing the girl (6)
I believe the answer is:
cashed
'realised' is the definition.
(I've seen this before)
'bounder is embracing the girl' is the wordplay.
'bounder' becomes 'cad' (synonyms).
'is embracing' indicates putting letters inside.
'the girl' becomes 'she' (I've seen this in another clue).
'cad' going around 'she' is 'CASHED'.
'the' acts as a link.
(Other definitions for cashed that I've seen before include "Got ready" , "Got money for the cheque" , "Realised" , "Exchanged for money, as cheque in bank" .)