Utopian novel of 1872 (7)
I believe the answer is:
'utopian novel of 1872' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for erewhon that I've seen before include "Satirical novel" , "LITERATURE" , "Book by Samuel Butler" , "Samuel Butler's utopian satire" , "Samuel Butler's utopia" .)