The end of Ronaldo's last game broadcast (5)
I believe the answer is:
omega
'the end' is the definition.
(last letter of the Greek alphabet)
'ronaldo's last game broadcast' is the wordplay.
'last' indicates one should take the final letters.
'broadcast' indicates an anagram (letters scattered or cast around).
The last letter of 'ronaldo' is 'o'.
'game' is an anagram of 'mega'.
'o'+'mega'='OMEGA'
'of' acts as a link.
(Other definitions for omega that I've seen before include "Foreign character" , "Greek character symbolizing resistance" , "Final outcome" , "completes a series" , "in Greece, the limit!" .)