One who guides bullocks to west of island (9)
I believe the answer is:
steersman
'one who guides' is the definition.
'bullocks to west of island' is the wordplay.
'bullocks' becomes 'steers' ('steer' can be a synonym of 'bullock').
'to west of' is a charade indicator (letters next to each other) (some letters go to the left of others).
'island' becomes 'man' (Man is an example).
'steers'+'man'='STEERSMAN'
(Other definitions for steersman that I've seen before include "Guide for sea voyage" , "One at ship's helm" , "Chap at the helm" .)