Wrongdoer and bad tipper? (8)
I believe the answer is:
offender
'wrongdoer' is the definition.
(I know that wrongdoer can be written as offender)
'bad tipper?' is the wordplay.
'bad' becomes 'off' (eg meat that's gone off is bad).
'tipper?' becomes 'ender' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'off'+'ender'='OFFENDER'
'and' acts as a link.
Can you help me to learn more?
(Other definitions for offender that I've seen before include "Culprit" , "miscreant" , "Committer of illegal act" , "One breaking rule" , "Wrongdoer" .)