Nothing seen in cutting pack of cards (5)
I believe the answer is:
tarot
'pack of cards' is the definition.
(I've seen this before)
'nothing seen in cutting' is the wordplay.
'nothing' becomes 'O' (O resembles 0).
'seen in' indicates putting letters inside.
'cutting' becomes 'tart' (both can mean sharp or sarcastic).
'o' put into 'tart' is 'TAROT'.
(Other definitions for tarot that I've seen before include "Playing cards" , "Sort of cards" , "78-card pack" , "Cards often used in fortune-telling" , "These cards are used to tell fortunes" .)