Excitement the malefactor could do without! (4)
I believe the answer is:
stir
'excitement' is the definition.
(synonyms)
'the malefactor could do without' is the wordplay.
I cannot really understand how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found in the answer.
The remaining letters 'sir' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for stir that I've seen before include "in which you'll find people with convictions" , "Ado" , "Thrill" , "Detention centre" , "Start to move" .)