The ship has gone off with everybody aboard it (7)
I believe the answer is:
galleon
'the ship' is the definition.
(type of ship)
'gone off with everybody aboard it' is the wordplay.
'gone off' becomes 'gon' (I can't justify this - if you can you should believe this answer much more).
'with' is an insertion indicator.
'everybody' becomes 'all' (I've seen this before).
'aboard' indicates putting letters inside (the inserted letters climb 'aboard').
'it' becomes 'e' ('e' can mean 'electronic' which is similar to 'IT').
'gon' going around 'all' is 'gallon'.
'gallon' enclosing 'e' is 'GALLEON'.
'has' is the link.
Can you help me to learn more?
(Other definitions for galleon that I've seen before include "Historical warship with three or more masts" , "Trader" , "Old Spanish ship" , "One might sink" , "Ship of the line" .)