Sailor having to return fortune-teller's cards (5)
I believe the answer is:
tarot
'fortune-teller's cards' is the definition.
(I've seen this before)
'sailor having to return' is the wordplay.
'sailor' becomes 'tar' (tar can mean a sailor).
'having' is a charade indicator (letters next to each other).
'return' shows that the letters should be reversed in order.
'to' reversed gives 'ot'.
'tar'+'ot'='TAROT'
(Other definitions for tarot that I've seen before include "Cards often used in fortune-telling" , "Picture card" , "Special cards for fortune-telling" , "one may have been taken from deck" , "One in special suit" .)