Want nine seeds to flourish (9)
I believe the answer is:
neediness
'want' is the definition.
(I know that want can be written as neediness)
'nine seeds to flourish' is the wordplay.
'to flourish' is an anagram indicator (I've seen 'flourishing' mean this (letters grow or flourish differently)).
'nine'+'seeds'='nineseeds'
'nineseeds' anagrammed gives 'NEEDINESS'.
(Other definitions for neediness that I've seen before include "Poverty" , "Insecurity" , "Destitution" , "Wanting state" , "Want" .)