Men regard unusual flower (9)
I believe the answer is:
germander
'flower' is the definition.
(I've seen this before)
'men regard unusual' is the wordplay.
'unusual' indicates anagramming the letters.
'men'+'regard'='menregard'
'menregard' with letters rearranged gives 'GERMANDER'.
(Other definitions for germander that I've seen before include "Flower" , "European plant" , "Plant of the mint family" .)