Fix in advance (3)
I believe the answer is:
rig
'fix in advance' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for rig that I've seen before include "Masts, spars and sails on a vessel" , "Apparatus; (boat's) sails" , "Oil-drilling device" , "Manipulate; (oil exploration) apparatus" , "Kit" .)