French and English are backing excise (5)
I believe the answer is:
erase
'excise' is the definition.
The answer and definition can be both to do with contact as well as being verbs in their base form.
Maybe there's an association between them I don't understand?
'french and english are backing' is the wordplay.
'french and english' becomes 'es' (I can't explain this - if you can you should believe this answer much more).
'backing' says the letters should be written in reverse.
'es'+'are'='esare'
'esare' reversed gives 'ERASE'.
Can you help me to learn more?
(Other definitions for erase that I've seen before include "Rub out, cancel" , "score" , "Blot out" , "Efface" , "Blank out" .)