Field event broadcast live in January (7)
I believe the answer is:
javelin
'field event' is the definition.
(javelin is a kind of field event)
'broadcast live in january' is the wordplay.
'broadcast' indicates anagramming the letters.
'in' is an insertion indicator.
'january' becomes 'jan' ('Jan' can be a synonym of 'january').
'live' is an anagram of 'veli'.
'veli' going within 'jan' is 'JAVELIN'.
(Other definitions for javelin that I've seen before include "Spear for throwing" , "Type of spear" , "Field event projectile" , "Long spear" , "It's thrown in a field event" .)