First-class chaps raised single flower (7)
I believe the answer is:
anemone
'flower' is the definition.
(I know that anemone is a type of flower)
'first-class chaps raised single' is the wordplay.
'first class' becomes 'A' (as in A-list, A-team etc).
'chaps' becomes 'men' (chap means a man).
'raised' shows that the letters should be reversed in order (going up in a down clue).
'single' becomes 'one' (a single thing - only one).
'men' reversed gives 'nem'.
'a'+'nem'+'one'='ANEMONE'
(Other definitions for anemone that I've seen before include "bloomer" , "Brightly coloured flower or tube-shaped sea creature" , "Sea creature, also flower" , "Flowering plant - mean one (anag)" , "Plant of the buttercup family with brightly coloured flowers" .)