Talk about seconds on field event (7)
I believe the answer is:
discuss
'talk about' is the definition.
('discuss' can be a synonym of 'talk about')
'seconds on field event' is the wordplay.
'seconds' becomes 's'.
'on' means one lot of letters go next to another.
'field event' becomes 'discus' (discus is a kind of field event).
's' put after 'discus' is 'DISCUSS'.
(Other definitions for discuss that I've seen before include "Talk about (something)" , "Argue" , "Consider" , "Go into" , "Take up" .)