Extreme cuts uncovered the majority (6)
I believe the answer is:
utmost
'extreme' is the definition.
('utmost' can be a synonym of 'extreme')
'cuts uncovered the majority' is the wordplay.
'uncovered' means to look at the middle letters.
'the majority' becomes 'most' (I've seen this before).
The middle letters of 'cuts' are 'ut'.
'ut'+'most'='UTMOST'
(Other definitions for utmost that I've seen before include "'Most extreme, greatest (6)'" , "At furthest limit" , "Maximum effort" , "Paramount" , "The greatest possible degree" .)