Cattle worker departs with rambler (6)
I believe the answer is:
drover
'cattle worker' is the definition.
'departs with rambler' is the wordplay.
'departs' becomes 'd' (common abbreviation e.g. train timetables).
'with' is a charade indicator (letters next to each other).
'rambler' becomes 'rover' (I've seen this before).
'd'+'rover'='DROVER'
(Other definitions for drover that I've seen before include "One driving cattle" , "One moving a herd or flock" , "I bring along many animals" , "Person moving sheep or cattle from one place to another" , "Cattle hand" .)