After trimming top, ship worker set off (7)
I believe the answer is:
trigger
'set off' is the definition.
(synonyms)
'after trimming top ship worker' is the wordplay.
I cannot really understand how this works, but
'worker' could be 'rigger' (rigger is a kind of worker) and 'rigger' is located in the answer.
A single letter 't' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for trigger that I've seen before include "Cause (device) to operate" , "Activating device" , "Equine film star" , "Gun firing device" , "One pulled to fire" .)