Very angry missing start of exciting sporting event (10)
I believe the answer is:
rallycross
'sporting event' is the definition.
(I've seen this before)
'very angry' is the wordplay.
'very' becomes 'rally' (I can't explain this - if you can you should give a lot more credence to this answer).
'angry' becomes 'cross' (cross can mean annoyed or angry).
'rally'+'cross'='RALLYCROSS'
'missing start of exciting' is the link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for rallycross that I've seen before include "sporting event" , "Motor sport" , "it's driven in competitively" , "Car event" , "off-road racing" .)