Oblique directions appended to petition (5)
I believe the answer is:
askew
'oblique' is the definition.
(I've seen this before)
'directions appended to petition' is the wordplay.
'directions' becomes 'ew' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'appended to' means one lot of letters go next to another.
'petition' becomes 'ask'.
'ew' after 'ask' is 'ASKEW'.
(Other definitions for askew that I've seen before include "Wonky" , "Twisted" , "Leaning to one side" , "Not straight or level, crooked" , "Obliquely" .)