Flower I water is ruined (8)
I believe the answer is:
wisteria
'flower' is the definition.
(thesaurus)
'i water is ruined' is the wordplay.
'ruined' is an anagram indicator.
'i'+'water'+'is'='iwateris'
'iwateris' is an anagram of 'WISTERIA'.
(Other definitions for wisteria that I've seen before include "As I write badly about the flowering vine" , "A flower, I swear it" , "I saw tire in this vine with the long flower clusters" , "Large climbing shrub, often attached to house" , "Vine with pendulous clusters of flowers" .)