Impartial earl with nut, crushed (7)
I believe the answer is:
neutral
'impartial' is the definition.
(I've seen this in another clue)
'earl with nut crushed' is the wordplay.
'with' says to put letters next to each other.
'crushed' indicates an anagram.
'earl' put after 'nut' is 'nutearl'.
'nutearl' anagrammed gives 'NEUTRAL'.
(Other definitions for neutral that I've seen before include "Not partisan or supporting either side in dispute" , "Unaligned" , "Impartial; plug wire" , "Renault (anag.)" , "Not siding with any party" .)