Deviant sailor wandering (8)
I believe the answer is:
aberrant
'deviant' is the definition.
(synonyms)
'sailor wandering' is the wordplay.
'sailor' becomes 'ab' (abbreviation for able seaman).
'wandering' becomes 'errant' (I've seen this before).
'ab'+'errant'='ABERRANT'
(Other definitions for aberrant that I've seen before include "Morally deviating" , "Divergent from the normal" , "Going wrong" , "Departing from accepted standard" , "Transgressing" .)