Attractive person cut flower? Calamity! (8)
I believe the answer is:
disaster
'calamity' is the definition.
(calamity can mean a disaster)
'attractive person cut flower?' is the wordplay.
'attractive person' becomes 'dish' (dish can mean an attractive person).
'cut' means to remove the last letter.
'flower?' becomes 'aster' (type of flower).
'dish' with its final letter taken away is 'dis'.
'dis'+'aster'='DISASTER'
(Other definitions for disaster that I've seen before include "Terrible calamity" , "Star dies (anag)" , "Tragedy of asterids" , "Catastrophic occurrence" , "Extreme ruin or misfortune" .)