Covering Oscars in high definition (4)
I believe the answer is:
hood
'covering' is the definition.
(hood is a kind of covering)
'oscars in high definition' is the wordplay.
'oscars in' becomes 'hoo' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'high' indicates taking the first letters (I've seen 'highest of' mean this (top letter - down clues only)).
The first letter of 'definition' is 'd'.
'hoo'+'d'='HOOD'
Can you help me to learn more?
(Other definitions for hood that I've seen before include "Capital cover" , "Part of subfusc" , "Bronx district" , "this could provide cover" , "Bonnet (US) - gangster (US)" .)