An American theatre award going to maiden opposite (7)
I believe the answer is:
antonym
'opposite' is the definition.
('antonym' can be a synonym of 'opposite')
'an american theatre award going to maiden' is the wordplay.
'an american theatre award' becomes 'antony' (I've seen this in other clues).
'going to' says to put letters next to each other.
'maiden' becomes 'm' (cricket abbreviation).
'antony'+'m'='ANTONYM'
(Other definitions for antonym that I've seen before include "Opposite-meaning word" , "One's import is contrary" , "Nick's could be free" , "Word that means the opposite of another" , "opposing description" .)