Ticket seller cooler after fight cancelled (3,6)
I believe the answer is:
box office
'ticket seller' is the definition.
(as in a cinema box office)
'cooler after fight cancelled' is the wordplay.
'cooler' becomes 'ice' (something which cools).
'after' means one lot of letters go next to another.
'fight' becomes 'box' (boxing is a kind of fighting).
'cancelled' becomes 'off' (similar in meaning).
'box'+'off'='boxoff'
'ice' after 'boxoff' is 'BOX-OFFICE'.
(Other definitions for box office that I've seen before include "ability to draw an audience" , "Where tickets are sold in a theatre" , "Place where theatre tickets are purchased" .)