Different hybrid of white rose (9)
I believe the answer is:
otherwise
'different' is the definition.
(I've seen this before)
'hybrid of white rose' is the wordplay.
'hybrid of' indicates anagramming the letters (I've seen 'hybrid' mean this (I've seen this in other clues)).
'white'+'rose'='whiterose'
'whiterose' is an anagram of 'OTHERWISE'.
(Other definitions for otherwise that I've seen before include "As an alternative - like white rose" , "Under different conditions" , "In other respects or ways" , "Differently - or else!" , "White rose seen in a different way" .)