Possible benefit sailor claimed (6)
I believe the answer is:
doable
'possible' is the definition.
('doable' can be similar in meaning to 'possible')
'benefit sailor claimed' is the wordplay.
'benefit' becomes 'dole' (I've seen this before).
'sailor' becomes 'ab' (abbreviation for able seaman).
'claimed' means one lot of letters goes inside another.
'dole' going around 'ab' is 'DOABLE'.
(Other definitions for doable that I've seen before include "easy to achieve" , "possible" , "Able to be carried out" , "Achievable, performable" .)