Endlessly talk about track event (6)
I believe the answer is:
discus
'track event' is the definition.
'discus' can be an answer for 'event' (athletics event). I am not sure about the 'track' bit.
'endlessly talk about' is the wordplay.
'endlessly' means to remove the last letter.
'talk about' becomes 'discuss' (to discuss something is to talk about it).
'discuss' with its last letter taken off is 'DISCUS'.
Can you help me to learn more?
(Other definitions for discus that I've seen before include "missile launched" , "Athletic field event" , "sports event" , "It is thrown in athletic events" , "Sporting missile" .)