Climber writes a novel about island (8)
I believe the answer is:
wisteria
'climber' is the definition.
(the wisteria is a climbing plant)
'writes a novel about island' is the wordplay.
'novel' is an anagram indicator.
'about' means one lot of letters goes inside another.
'island' becomes 'i'.
'writes'+'a'='writesa'
'writesa' with letters rearranged gives 'wistera'.
'wistera' placed around 'i' is 'WISTERIA'.
(Other definitions for wisteria that I've seen before include "Climbing lilac-flowered shrub" , "I swear it is a flowering vine" , "Climber" , "Vine with pendulous clusters of flowers" , "climbing plant" .)