Set difficult directions (6)
I believe the answer is:
harden
'set' is the definition.
(I've seen this in another clue)
'difficult directions' is the wordplay.
'difficult' becomes 'hard' (synonyms).
'directions' becomes 'en' (east and north).
'hard'+'en'='HARDEN'
(Other definitions for harden that I've seen before include "Small fly" , "Steel oneself" , "Become firm and solid" , "Grow more firm" , "Temper, steel say" .)