Threw overboard (10)
I believe the answer is:
jettisoned
'threw overboard' is the definition.
('jettison' can be a synonym of 'throw overboard')
This is all the clue.
(Other definitions for jettisoned that I've seen before include "Thrown overboard" , "dumped" , "thrown out of plane" , "Discarded" , "Ditched" .)