At sixes and sevens, turn to her for direction (4,5)
I believe the answer is:
true north
'direction' is the definition.
(I've seen this before)
'at sixes and sevens turn to her' is the wordplay.
'at sixes and sevens' is an anagram indicator.
'turn'+'to'+'her'='turntoher'
'turntoher' anagrammed gives 'TRUE NORTH'.
'for' is the link.
(Other definitions for true north that I've seen before include "In the direction of one of the poles" , "Position of maximum latitude" , "Pole" , "rarely needled when on the move" , "Direction aligned with earth's axis" .)