Talk about short field event (6)
I believe the answer is:
discus
'field event' is the definition.
(discus is a kind of field event)
'talk about short' is the wordplay.
'talk about' becomes 'discuss' (to discuss something is to talk about it).
'short' means to remove the last letter.
'discuss' with its last letter taken away is 'DISCUS'.
(Other definitions for discus that I've seen before include "It is thrown in athletic events" , "Object thrown in field sports" , "Field sport" , "flat missile" , "sports event" .)