Nosegays (6)
I believe the answer is:
'nosegays' is the definition.
('posy' can be a synonym of 'nosegay')
This is all the clue.
(Other definitions for posies that I've seen before include "'Corsages, small bouquets (6)'" , "Sprays" , "Poises with bunches of flowers" , "Small bunches of flowers (a pocketful?)" , "Nosegays" .)