Flower you originally put on platform (5)
I believe the answer is:
daisy
'flower' is the definition.
(I know that daisy is a type of flower)
'you originally put on platform' is the wordplay.
'you originally' becomes 'y' (I can't justify this - if you can you should give a lot more credence to this answer).
'put on' says to put letters next to each other.
'platform' becomes 'dais' (dais is a kind of platform).
'y' put after 'dais' is 'DAISY'.
(Other definitions for daisy that I've seen before include "Flower of lawn and meadow" , "Common plant" , "Lawn flower, weed" , "See 1 Across" , "Common wildflower" .)