Safe directions on remedy (6)
I believe the answer is:
secure
'safe' is the definition.
(I know that safe can be written as secure)
'directions on remedy' is the wordplay.
'directions' becomes 'se' (I've seen this in other clues).
'on' is a charade indicator (letters next to each other) (in a down clue, letters appear on others).
'remedy' becomes 'cure' (synonyms).
'se'+'cure'='SECURE'
(Other definitions for secure that I've seen before include "Firm; safe" , "land" , "lock" , "Firmly fixed or free from uncertainty" , "properly restrained" .)