Thomas More work (6)
I believe the answer is:
utopia
'thomas more work' is the definition.
(I know that Utopia author Thomas More)
This is the entire clue.
(Other definitions for utopia that I've seen before include "place of bliss" , "More's ideal world" , "Thomas More's 1516 book about life on an imaginary island" , "impossible to find" , "Thomas More's favourite place" .)