Critic of big country half ignored by relations (6)
I believe the answer is:
ruskin
'critic' is the definition.
(I know that Ruskin is a art critic)
'big country half ignored by relations' is the wordplay.
'big country' becomes 'Russia' (Russia is a large country).
'half ignored' means to take half the letters.
'by' says to put letters next to each other.
'relations' becomes 'kin' (both can mean one's family).
'russia' with half the letters taken is 'rus'.
'rus'+'kin'='RUSKIN'
'of' acts as a link.
(Other definitions for ruskin that I've seen before include "Victorian writer" , "John --. C19 art and social critic" , "English author" , "John -, nineteenth century English social critic" , "John -, Victorian author, poet and artist" .)