Flag duly rising on our pole, first of all (5)
I believe the answer is:
droop
'flag' is the definition.
(I know that flag can be written as droop)
'duly rising on our pole first of all' is the wordplay.
'first of all' indicates taking the first letters.
The first letters of 'duly rising on our pole' is 'DROOP'.
(Other definitions for droop that I've seen before include "Hang limply" , "Decline" , "Become limp" , "male problem?" , "Hang downwards, lose strength or spirit" .)