Jack returned to deck of cards (5)
I believe the answer is:
tarot
'deck of cards' is the definition.
(deck of cards for fortune telling)
'jack returned to' is the wordplay.
'jack' becomes 'tar' (both are informal terms for sailor).
'returned' is a reversal indicator.
'to' reversed gives 'ot'.
'tar'+'ot'='TAROT'
(Other definitions for tarot that I've seen before include "Picture card" , "Arcana cards" , "Sort of cards" , "Cards often used in fortune-telling" , "Fortune teller's seventy eight card pack" .)