Elizabeth, a superior lady deserted by a sailor (4)
I believe the answer is:
bess
'elizabeth' is the definition.
(nickname)
'a superior lady deserted by a sailor' is the wordplay.
'a superior lady' becomes 'abbess' (I've seen this before).
'deserted by' suggests deleting specific letters.
'a sailor' becomes 'ab' (abbreviation for able seaman).
'abbess' with 'ab' taken out is 'BESS'.
(Other definitions for bess that I've seen before include "Queen Elizabeth 1 (sl)" , "Operatic mate for Porgy" , "Nickname for English queen" , "Our Good Queen" , "Elizabeth (dim.)" .)