Sad beauty cut flower (8)
I believe the answer is:
bluebell
'flower' is the definition.
(I've seen this before)
'sad beauty cut' is the wordplay.
'sad' becomes 'blue' (similar in meaning).
'beauty' becomes 'belle' (I've seen this before).
'cut' means to remove the last letter.
'belle' with its final letter removed is 'bell'.
'blue'+'bell'='BLUEBELL'
(Other definitions for bluebell that I've seen before include "Wild flowers with bell-shaped heads" , "girl in 1930s dance troupe?" , "natural growth" , "Wildflower" , "It's also called wild hyacinth" .)