Neglect to order it (4)
I believe the answer is:
omit
'neglect' is the definition.
('omit' can be a synonym of 'neglect')
'order it' is the wordplay.
'order' becomes 'om' (order of merit).
'om'+'it'='OMIT'
'to' acts as a link.
(Other definitions for omit that I've seen before include "Leave out or forget" , "Leave out or neglect" , "Neglect to include" , "Leave out, perhaps in error" , "Fail to use" .)