Ward off offender in fonder offending (7)
I believe the answer is:
forfend
'ward off' is the definition.
(I know that ward off can be written as forfend)
'offender in fonder offending' is the wordplay.
I cannot quite see how this works, but
an anagram of 'fonder' is 'orfend' which is present in the answer.
A single letter 'f' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Another definition for forfend that I've seen is " Prevent".)