Robust novelist? (5)
I believe the answer is:
hardy
This clue is a double definition.
'robust' is the first definition.
(similar in meaning)
'novelist?' is the second definition.
(Hardy is a novelist)
(Other definitions for hardy that I've seen before include "Resistant to frost etc" , "Author of Jude the Obscure" , "flag-captain" , "Author - robust" , "16 novelist" .)