Bird about to go north, then north-east (4)
I believe the answer is:
erne
'bird' is the definition.
(erne is a kind of bird)
'to go north then north-east' is the wordplay.
'to go' becomes 're' (I've seen this in other clues).
'north' says the letters should be written backwards (in a down clue, letters go up or 'northward').
'then' means one lot of letters go next to another.
'north east' becomes 'ne'.
're' backwards is 'er'.
'er'+'ne'='ERNE'
'about' acts as a link.
(Other definitions for erne that I've seen before include "Irish lough" , "Seabird" , "White-tailed eagle" , "Fish-eating sea eagle" , "one that catches fish?" .)