The bandit gets on to the ship as well (7)
I believe the answer is:
brigand
'the bandit' is the definition.
(synonyms)
'on to the ship as well' is the wordplay.
'on' says to put letters next to each other.
'to the ship' becomes 'brig' (I've seen this before).
'as well' becomes 'and' (I've seen this in other clues).
'brig' next to 'and' is 'BRIGAND'.
'gets' is the link.
(Other definitions for brigand that I've seen before include "Gang member" , "Robber in wild places" , "Highway robber" , "Criminal" , "Robber in a gang" .)