Leave scene contaminated by sailor (7)
I believe the answer is:
absence
'leave' is the definition.
(thesaurus)
'scene contaminated by sailor' is the wordplay.
'contaminated' indicates anagramming the letters (a corrupted spelling).
'by' is a charade indicator (letters next to each other).
'sailor' becomes 'ab' (abbreviation for able seaman).
'scene' with letters rearranged gives 'sence'.
'sence' put after 'ab' is 'ABSENCE'.
(Other definitions for absence that I've seen before include "Non-attendance" , "Need" , "''. . . . . . . makes the heart grow fonder'' (7)" , "Failure to attend" , "Lack - it makes the heart grow fonder" .)