Sailor in charge, in time, quit (8)
I believe the answer is:
abdicate
'quit' is the definition.
(I've seen this before)
'sailor in charge in time' is the wordplay.
'sailor' becomes 'ab' (abbreviation for able seaman).
'in charge' becomes 'ic'.
'in' is an insertion indicator.
'time' becomes 'date' (date is a kind of time**).
'ic' inserted into 'date' is 'dicate'.
'ab'+'dicate'='ABDICATE'
(Other definitions for abdicate that I've seen before include "Formally renounce throne, power etc" , "Abandon" , "Resign from monarchy" , "Give up a throne" , "Renounce one's throne" .)